null  null
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USOO5663682A
United States Patent [191
5,663,682
[11] Patent Number:
[45] Date of Patent:
Meline et a].
Sep. 2, 1997
Primary Examiner-4teven J. Mottola
[54] WIDE BANDWIDTH COMBINER
AMPLIFIER
Attorney Agent, or Finn-Merchant, Gould, Smith, Edell,
Welter & Schmidt, BA.
[75] Inventors: Reuben W. Meline, Crystal; Jeifrey 0.
Brown, St. Paul, both of Minn.
[57]
ABSTRACT
[73] Assignee: ADC Telecommunications, Inc.,
A combiner-ampli?er is provided which has ?rst current
feedback ampli?er which ampli?es a ?rst received signal by
a predetermined gain value. A second current feedback
[21] Appl. No.: 553,760
Oct. 23, 1995
[22] Filed:
[5 1] Int. C16 ...................................................... .. H03!‘ 3/68
.. 330/124 R; 330/84
[52]
[58] Field of Search ................................ .. 330/84, 124 R,
ampli?er ampli?es a second received signal by the prede
termined gain value. A combiner is operatively coupled to
Minneapolis, Minn.
the ?rst and the second current feedback ampli?ers to
combine the ampli?ed ?rst received signal with the second
received signal together to generate a combined signal
which is attenuated by the predetermined gain value such
330/147, 284, 295
that the combined signal has approximately a unity gain over
the ?rst and the second received signals within a bandwidth
of at least 45 megahertz.
References Cited
[56]
U.S. PATENT DOCUMENTS
5,256,987
18 Claims, 4 Drawing Sheets
10/1993 Kibayashi et a1. .................... .. 330/295
152 [154
[156
5 OHM
BUFFER
>— TERMINAL a GA'“ = 8 —’:
164
f
166
168 170
172
[
:
158
f 150
>_ 75 OHM
TERMINIAL
'
‘
r162
____> BUFFER
GAIN = 8
GAIN _1,16
178
174 f
OUTPUT
75 OHM
GAIN = 4
TERMINAL
176
26 DB
182
180
9
183
ATfENUA?ON ‘Q
CIRCUIT
184
US. Patent
Sep. 2, 1997
Sheet 3 0f 4
5,663,682
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US. Patent
Sep. 2, 1997
Sheet 4 of 4
5,663,682
274
6FIG.
242
£244
5,663,682
2
1
FIG. 3 is a block diagram of a preferred embodiment
WIDE BANDWIDTH COMBINER
AMPLIFIER
combiner-ampli?er.
FIG. 4 is a circuit diagram of the preferred embodiment
FIELD OF THE INVENTION
power supply shown in FIG. 2.
FIG. 5 is a circuit diagram of the input and buifer portion
of the preferred embodiment combiner-ampli?er shown in
The present invention relates generally to a signal com
biner. More particularly, the present invention relates to such
a combiner exhibiting an overall unity gain by having an
FIG. 3.
active ampli?er circuit.
BACKGROUND OF THE INVENTION
10
The cable television (CATV) market place has used
splitter/combiner products to manage video signal distribu
tion since the industry began in the early 1950s. This ?rst
industrial application evolved into a consumer/residential
15
application during the 1970s. Today, the delivery of video
services is growing fast and deregulation of the CATV
market is near. Furthermore, the bandwidth requirement is
increasing with new modulator technology. New modulators
are capable of 750-860 megahertz (MHz) signals rather than
the 450 MHz output previously available.
Tradiu'onally signals for CATV travel in the outbound
20
direction from the headend or distribution point to the
customer or home residences. However, with the advent of
interactive CATV it is now necessary to pass signal both
outbound and inbound (i.e. from the customer back to the
25
FIG. 6 is a circuit diagram of the summing circuit, output
ampli?er, and output portion of the preferred embodiment
combiner-ampli?er shown in FIG. 3.
DETAILED DESCRIPTION
Referring now to FIG. 1, a CATV signal communication
system 100 is shown. A typical CATV system, like the one
shown in FIG. 1 includes several residences/customers 108,
110. One or more customers may be grouped together and
split from a common tap. For example, a group of 11
customers 108 are split from an n-way tap 112. Similarly, a
group of m customers 110 are split from an m-way tap 114.
Each tap 112 and 114 are feed from a common node trunk
line 102 through trunk ampli?ers 104 and 106, respectively.
The trunk ampli?ers 104, 106 are placed at each signal split
point to compensate for the loss of average signal power due
to the signal splitting and potentially any line loss that has
occurred between trunk ampli?ers. The trunk line 102
extends through all of the branches and terminates at one
end.
The other end of the trunk line 102 is connected to a ?nal
headend). This can be accomplished by using different
frequency bands on the same cable for inbound and out
bound communication. But, this leads to needing a receiver
trunk ampli?er 116 which in turn is connected to diplex ?lter
at the headend for each customer. Such a requirement is not 30 122 within the headend or distribution point 118 The diplex
cost effective. Therefore, a need exists for a way to reduce
?lter 122 is a bi-directional device which splits off the
the number of receivers needed at the headend
inbound signals to the headend 118 and sends them to an
The present invention provides a solution to this and other
problems, and o?’ers other advantages over the prior art.
input of the combiner-ampli?er 124. The inbound signals
35
SUMIvlARY OF THE INVENTION
may be present within the 5 to 50 or 200 MHz frequency
band and as such the combiner-ampli?er 124 should be able
to simultaneously combine signals within this wide band
width. The combiner-ampli?er 124 combines inbound sig
nals from sixteen di?’erent nodes attached through diplex
?lter 120, 122 into a combined signal. The combined signal
The present invention relates to signal ampli?ers and
combiners that operate over a wide frequency bandwidth to
combine signals from two or more customers into a com
' bined multiplexed signal that can be routed on a communi
is received by a receiver 126 which in turn provided all or
part 'of the combined signal to a processor/controller 128
which controls operations of the headend 118. The
cation channel to a receiver circuit at the headend.
In accordance with one aspect of the invention, a
processor/controller 128 also controls operations of the
headend transmitting equipment 130 which supplies out
bound signals to a headend splitter 132. The headend splitter
132 splits the outbound signal among several diplex ?lter
combiner-ampli?er is provided which has ?rst current feed
back ampli?er which ampli?es a ?rst received signal by a
predetermined gain value. A second current feedback ampli
?er ampli?es a second received signal by the predetermined
gain value. A combiner is operatively coupled to the ?rst and
120, 122 which add the outbound signals to the trunk line
102 and forwards those signals to the customers. The
the second current feedback ampli?ers to combine the
outbound
signal for CATV systems is typically a wide
ampli?ed ?rst received signal with the second received 50 bandwidth composite signal between 50 or 200 and 750
signal together to generate a combined signal which is
MHZ.
attenuated by the predetermined gain value such that the
combined signal has approximately a unity gain over the
?rst and the second received signals within a bandwidth of
at least 45 megahertz.
The present invention can be summarized in reference to
FIGS. 2 and 3 which are block diagrams of the preferred
55
These and various other features as well as advantages
which characterize the present invention will be apparent
upon reading of the following detailed description and
review of the associated drawings.
of the inputs receives a different received video signal from
an external source through one of the 16 “F”-style connec
tors. These are 75 ohm impedance connectors.
Sixteen current feedback ampli?ers (e.g., bu?‘er 156) are
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a signal cormnunication
system which utilizes one or more preferred embodiment
combiner-ampli?ers.
FIG. 2 is a block diagram of a preferred embodiment
power supply.
embodiment object combiner-ampli?er 124. The combiner
arnpli?er includes sixteen inputs (e.g., a combination of
input jack 152 and a 75 ohm terminator terminal 154). Each
65
operatively coupled to an associated input (e.g., terminal
154), respectively. Each of the feedback ampli?ers ampli?es
the received signal from the associated input by a gain of 8
times the average signal voltage.
A combiner is operatively coupled to each of the sixteen
current feedback ampli?ers. This combiner combines each
5,663,682
3
4
of the ampli?ed received signals together to generate a
combined signal which is attenuated by 8 times the average
placed into the CATV system 100. This is signi?cantly better
than the passive combiners which may introduce a signal
signal voltage such that the combined signal has approxi
loss of 8 to 16 dB upon insertion into the CATV system.
The following discussion is directed to the detailed circuit
mately a unity gain over the received signals within a
bandwidth of at least 45 megahertz. An output (i.e., a
combination of output jack 180 and a 75 ohm terminator
terminal 178) is operatively coupled to the combiner which
provides the combined signal to a device external to the
combiner-ampli?er 124. The terminator terminal 178 may
diagrams shown in FIGS. 4, 5 and 6. The following de?ni
tions in Table 1 may be helpful in understanding this
description:
TABLE 1
be implemented as a series connected 75 ohm resistor to a 10
“IF-style connector which properly terminates the output of
Baseband Video
the combiner-ampli?er 124.
The combiner-ampli?er 124 preferably utilizes compo
nents arranged in a particular circuit design (i.e., the sixteen
The standard composite video signal
comprising all video information,
synchronizing pulses, and audio information.
Cable TV signal
Covers the frequency range of approximately
F connector
54 to 552 MHz.
The standard 75 ohm coax cormector used in
Head-End
homes and businesses to interconnect video
and RF signals. The center conductor is the
physical center conductor wire of the coax
cable, and the shell is threaded.
The central location where the cable TV
Itspans the frequemyrangeof0to6MHz.
inputs, the sixteen current feedback ampli?ers, the
combiner, and the output) which can manipulate signals
between 5 megahertz and 200 megahertz such that the
output passes signals within the 5 megahertz to 200 mega
hertz frequency band from the inputs with approximately a
15
unity gain of average signal voltage over the frequency
20
band.
The combiner preferably includes a current feedback
NAB
NTSC
ampli?er-based summing circuit 164 which sums the ampli
?ed received signals together to form an intermediate signal
170. A signal splitter 172 is operatively coupled to an output
168 of the summing circuit 164 which splits the intermediate
signal 170 into the combined signal 174 and an output
monitoring signal 176. An attenuator circuit 182 is opera
tively coupled to the signal splitter 172 to attenuate an
average signal power of the output monitoring signal 176 by
signal is assembled, ampli?ed, and distributed
times an average signal voltage of each ampli?ed received
signal (e.g. from ampli?er 156) to an summed signal 166
which has an average signal voltage equal to 1Asth of each
SCTE
SMP'IE
Society of Motion Picture and
Television Engineers
Sub-split
30
Refers to the return signal from the customer
to the head-end. The customer set-top boxes
are not available to provide this signal yet, but
the cable TV companies have either installed
or are in the process of installing onto the
Sub-split signal
35
cable system the equiprnmt required to
handle this signal.
Covers a relatively small frequency range but
abandfromS MI-lzto SOMHz (orupto200
M1{zforsomerequirements)hasbeensetaside
for this return signal (from the customer
to the head-end).
Power to the on-board circuitry is provided by a high
e?iciency Universal Input-to-DC converter 200 shown in
FIG. 4. A green LED 204 in series with a 2100 ohm resistor
202 is connected across the output of the Universal Input
to-DC converter 200 to indicate when the combiner
ate signal 170 between the combined signal 174 and the
output monitoring signal 176.
ampli?er is operating. Capacitors 206 and 208 are used as
?lters to reduce the alternating current (AC) characteristics
of the positive side of the 12 volt power supply. In the
preferred embodiment these capacitors 206, 208 were cho
The combiner-ampli?er preferably includes a power sup
ply 144, shown in FIG. 2, which provides a voltage source
146 to active circuitry in the sixteen current feedback
nating Current (VAC) up to 250 VAC and 50 to 60 Hertz,
may be supplied at the power supply connector. An indicator
148 is operatively coupled to the power supply 144 which
indicates when the power supply 144 is activated For
example, this indicator may be an light emitting diode that
is illuminated when the power supply 144 is activated.
One of the advantages of the combiner-ampli?er 124 over
other types of designs is the use of operational ampli?ers to
compatible with black-and-white television.
Society of Cable and Telecommunications
Engineers
ampli?ed received signals. Subsequently, this signal 166 is
ampli?ed (e. g., with another current feedback ampli?er 168)
by approximately 4 times an average signal voltage to form
the intermediate signal 170. The signal splitter 172 then
equally divides the average signal voltage of the intennedi
ampli?ers (e.g., buffer 156) and the combiner (e.g., output
ampli?er 168). This power supply 144 preferably is
universal-type such that any voltage from 100 Volts Alter
National Television Standards Committee, the
committee that governs the color system
at least 26 decibels (dB) over an average signal power of the
combined signal 174. This attenuated output monitoring
signal 183 is provided to output jack 184.
The summing circuit 164 attenuates by approximately 16
from the cable TV operator to the customer.
National Association of Broadcasters
sen as a 2.2 microfarad (pF) 50 volt (V) capacitor and a 4300
50
picofarad (pF) 50 V capacitor, respectively. Similarly,
capacitors 210 and 212 are used as ?lters to reduce the
alternating current (AC) characteristics of the negative side
of the 12 volt power supply. In the preferred embodiment
these capacitors 210, 212 were chosen as a 2.2 microfarad
55
(uF) 50 volt (V) capacitor and a 4300 picofarad (pF) 50 V
capacitor, respectively.
Each operational ampli?er (op-amp) in the combiner
typically inject interference into the signal being communi
ampli?er requires +5 and —5 VDC at its power leads. The
power supply output is +12 and -l2 VDC, so 6.8 volt zener
diodes (e.g., zener diodes 214, 216 as shown in FIG. 5 for
one of vthe 16 input branches 152, 154, 156 as shown and
cated on the trunk line 102. Such interference may take the
form of cross talk and return loss. These types of interfer
ence are minimized in the active combiner-ampli?er
the power supply lines at every op-amp to drop the voltage
to the proper level. Each op-amp power supply lead is
eliminate the need for transformers or inductors which
described in the preferred embodiment. In addition, the
combiner-ampli?er 124 is a an active (i.e., powered) unity
gain combiner and as such has zero insertion loss when
described in reference to FIG. 3) are connected in series with
65
bypassed to common by two capacitors (e.g., capacitors 218,
220). One of them is a 0.1 pF ceramic capacitor (e.g.,
capacitor 218), the other is a 10 uF tantalum capacitor (e.g.,
5,663,682
5
6
capacitor 220). This provides a good combination of bypass
ing at low and high frequencies. The 0.1 pF capacitor is
The signals at the positive input of the output op-amp are
attenuated by the resistor network by a factor of 16. That, in
preferably placed as close as possible to the op-amp power
combination with the attenuation by a factor of 2 at the
pin for good high-frequency bypassing.
Each input 226 is DC blocked with a 0.1 pF capacitor 228,
output jack, is why the signal must be ampli?ed by a factor
of 32. All 16 signals are combined at the positive input of the
i then terminated with a 75 ohm resistor 230 to ground. The
. output op-amp 274, and are ampli?ed by a factor of 4. Since
input signal then connects to the positive input of a very high
this op-amp is also a current-feedback type, the feedback
resistor 276 is only 150 ohms, with a 49.9 ohm resistor 278
connected from the minus input to common. As noted before
the 3 to 1 ratio of the resistors is critical, but the particular
bandwidth op-amp 232. These are current-feedback type
op-arnps, and are connected to provide a non-inverting gain
of eight using a 475 ohm resistor 234 in the feedback loop,
and a 68.1 ohm resistor 236 from the minus input to
10
values may vary depending on the particular desired ampli
?er characteristics. The output pin connects to a 75 ohm
resistor 280, which connects to a 0.1 uF DC-blocking
capacitor, which then connects to the output jack 284. The
desired rollotf or voltage peak point. The output of the 15 monitor output also comes from the output pin, through a 0.1
common. The ratio of the values for these resistors 234 to
236 should be 7 to 1, but the particular values are trivial
except that they need to be chosen to obtain a particular
uF DC-blocking capacitor 286, to a 750 ohm resistor 288,
op-amp connects to a 75 ohm resistor 238, the other side of
which connects to a transmission line 240.
Transmission line 240 carries the signal to a 64.9 ohm
resistor (e. g., resistor 242) which is one of the 16 inputs of
the summing ampli?er circuit portion of the combiner
ampli?er as shown in FIG. 3. The other side of the resistor
242 connects to 64.9 ohm resistors 244 through 272 from the
outputs of the other 15 op-amps as well, so that the total
resistance at the end of the signal line looks like 75 ohms.
which connects to an 82.5 ohm resistor 290. This forms a26
dB voltage divider connecting to the monitor jack. These
resistor values were chosen so that, looking from the moni
20
tor jack back into the circuit, the impedance will be 75 ohms.
With these particular values for the various components,
the electrical operating characteristics for the preferred
embodiment unity gain combiner-ampli?er (UGC) are
shown in Table 2.
TABLE 2
Power InputVoltage to
16 X 1 UGC
Power Input
100 to 260 VAC
110 to 340 VDC
105 to 250 VAC
110 to 340 V'DC
110 to 240 VAC
120 to 320 VDC
45 to 65 Hz.
46 to 64 H1.
47 to 63 Hz.
50 mA max.
75 mA max.
100 mA max.
+12.0 V i 0.5 V
—12.0 V i 0.5 V
+120 V + 0.75 V NIA
—12.0 V + 0.75 V N/A
Comments
Frequency
to 16 X l UGC
Power Input
worst case
current to
16 X 1 UGC at
110 VAC
Internal
regulated
100 mA
load
voltages on
typical
16 X 1 UGC
100 mA
load
typical
Input
75 :t 1.0 ohms
75 i 1.0 ohms
75 :i: 1.3 ohms
>20 dB
>20 dB
>20 dB
75 i 1.0 ohms
75 :I: 1.0 ohms
75 i 1.3 ohms
33 dBmV
33 dBmV
3O dBmV
Impedance
Return Loss
at the
From 5 MHz
to 200 MHz
Inputs
Output
Impedance
Max. signal
»
input level
0 dBmV = 1
mV into 75
ohm
impedance
Max. signal
57 dBmV
57 dBmV
54 dBmV
output
level
0 dBmV : 1
mV into 75
ohm
impedance
Second
—60 dBc
-60 dBc
—-55 dBc
, @ 30 MHz,
Harmonic
30 dBmV
distortion
signal
input
Third
Harmonic
—70 dBc
—70 dBc
-60 dBc
distortion
@ 30 MHz,
30 dBmV
signal
input
Signal
isolation,
>50 db
>50 db
>45 db
From 5 MHz
to 200
input to
MHz, 30
input,
dBmV input
output to
input
Gain
Flatness
i.8dB
:t.8d.B
ildB
SMI-Izto
200 MHz
5,663,682
7
‘TABLE 2-continued
Insertion
Loss
Carrier-toNoise Ratio
OdBildB
OdBildB
OdB:t1.2dB
5 MHz to
200 MHz
48 dB minimum
48 dB minimum
45 dB minimum
Carrier
level is
20 dBmV
Noise
measured
over a 4
MHZ
bandwidth
over the
range of 5
Monitor
20 dB :t 1 dB
jack level
down from main
same
ame
to 200 MHz
5 MHz to
200 MHZ
output
It is to be understood that even though numerous char
acteristics and advantages of various embodiments of the
present invention have been set forth in the foregoing
description, together with details of the structure and func
tion of various embodiments of the invention, this disclosure
is illustrative only, and changes may be made in detail,
especially in matters of structure and arrangement of parts
within the principles of the present invention to the full
extent indicated by the broad general meaning of the terms
in which the appended claims are expressed For example,
the actual values of the circuit components (e. g., capacitors,
received signals with approximately a unity gain over the
20
3. The combiner-ampli?er of claim 1 wherein the com
biner means feedback ampli?er-based summing circuit sums
the ?rst and the second ampli?ed received signals together
25
be appreciated by those skilled in the art that the teachings
tively coupled to the signal splitter, which attenuates an
average signal voltage of the output monitoring signal by at
least 20 decibels over an average signal voltage of the
combined signal.
35
gain value, respectively.
from the scope and spirit of the present invention. Further,
7. The combiner-ampli?er of claim 6 wherein the prede
termined gain value is a gain of 8 such that each ampli?er
means ampli?es by approximately 8 times an average signal
voltage of an associated received signal and the combiner
a —48 volts direct current (VDC) powered version of the
combiner-ampli?er 124 also may be produced. Furthermore,
another embodiment of the combiner-ampli?er may have an
8 input, 4 parallel output device that uses BNC connectors
means attenuates by approximately 8 times an average
instead of “F’-type connectors for the video input and output
45
1. A combiner-ampli?er, comprising:
(a) ?rst feedback ampli?er means for amplifying a ?rst
received signal by a predetermined gain value;
(b) second feedback ampli?er means for amplifying a
8. The combiner-ampli?er of claim 1 further comprising
a power supply which provides a voltage source to active
circuitry in the ?rst feedback ampli?er means, the second
55 feedback ampli?er means, and the combiner means.
9. The combiner-ampli?er of claim 8 further comprising
an indicator, operatively coupled to the power supply, which
indicates when the power supply is activated.
10. A combiner-ampli?er, comprising:
(a) a ?rst input which received a ?rst signal;
(b) a second input which received a second signal;
over the ?rst and the second received signals within a
bandwidth of at least 45 megahertz.
2. The combiner-ampli?er of claim 1 wherein the ?rst
feedback ampli?er means, the second feedback ampli?er
means, and the combiner means each manipulate signals
between 5 megahertz and 200 megahertz such that the
combined signal passes signals within the 5 megahertz to
200 megahtrtz frequency band from the ?rst and the second
signal voltage of the combined signal, the summing circuit
attenuating by approximately 16 times an average signal
voltage of each ampli?ed received signal and subsequently
amplifying by approximately 4 times an average signal
voltage to form the intermediate signal, the signal splitter
equally dividing the average signal voltage of the interme
diate signal between the combined signal and the output
monitoring signal.
second received signal by the predetermined gain
value; and
(c) combiner means, operatively coupled to the ?rst and
the second feedback ampli?er means, for combining
the ampli?ed ?rst received signal with the second
received signal by utilizing a feedback ampli?er-based
summing circuit to generate a combined signal which is
attenuated by the predetermined gain value such that
the combined signal has approximately a unity gain
6. The combiner-ampli?er of claim 5 further comprising
a third through sixteenth feedback ampli?er means which
amplify an associated received signal with a predetermined
of the present invention can be applied to other communi
What is claimed is:
biner means further comprises a signal splitter, operatively
coupled to an output of the summing circuit which splits the
intermediate signal into the combined signal and an output
5. The combiner-ampli?er of claim 4 wherein the com
biner means further comprises an attenuator circuit, opera
cation systems, like ?ber optic networks, without departing
jacks.
to form an intermediate signal.
4. The combiner-ampli?er of claim 3 wherein the com
monitoring signal.
resistors, diodes, etc.) may vary depending on the particular
application for the combiner-ampli?er while maintaining
substantially the same functionality without departing from
the scope and spirit of the present invention. In addition,
although the preferred embodiment described herein is
directed to a combiner-ampli?er for a CATV system, it will
frequency band.
(c) a ?rst current feedback ampli?er, operatively coupled
to the ?rst input, which ampli?es the ?rst received
signal by a predetermined gain value;
65
(d) a second current feedback ampli?er, operatively
coupled to the second input, which ampli?es the second
received signal by the predetermined gain value;
5,663,682
10
current feedback ampli?er-based summing circuit to
generate a combined signal which is attenuated by 8
times such that the combined signal has approximately
(e) a combiner, operatively coupled to the ?rst and the
second current feedback ampli?er, which combines the
ampli?ed ?rst received signal with the second received
a unity gain over the received signals within a band
width of at least 45 megahertz; and
signal by utilizing a feedback ampli?er-based summing
circuit to generate a combined signal which is attenu
ated by the predetermined gain value such that the
combined signal has approximately a unity gain over
(d) an output, operatively coupled to the combiner, which
the ?rst and the second received signals within a
bandwidth of at least 45 megahertz; and
14. The combiner-ampli?er of claim 13 wherein the
sixteen inputs, the sixteen current feedback ampli?ers, the
(f) an output, operatively coupled to the combiner, which
provides the combined signal.
provides the combined signal.
10
signals within the S megahertz to 200 megahertz frequency
11. The combiner-ampli?er of claim 10 wherein the ?rst
input, the second input, the ?rst current feedback ampli?er,
the second current feedback ampli?er, the combiner, and the
output each manipulate signals between 5 megahertz and
200 megahertz such that the output passes signals within the
band from the inputs with approximately a unity gain over
15
5 megahertz to 200 megahertz frequency band from the ?rst
and the second inputs with approximately a unity gain over
the frequency band.
12. The combiner-ampli?er of claim 11 wherein:
(a) the feedback ampli?er-based summing circuit includes
coupled to an output of the summing circuit which
splits the intermediate signal into the combined signal
and an output monitoring signal; and
(c) the combiner comprises an attenuator circuit, opera
tively coupled to the signal splitter, which attenuates an
the second ampli?ed received signals together to form
an intermediate signal;
25
the combined signal.
splits the intermediate signal into the combined signal
and an output monitoring signal; and
(c) the combiner comprises an attenuator circuit, opera
tively coupled to the signal splitter, which attenuates an
16. The combiner-ampli?er of claim 15 wherein the
summing circuit attenuates by approximately 16 times an
average signal voltage of each ampli?ed received signal and
subsequently ampli?es by approximately 4 times an average
signal voltage to form the intermediate signal, and the signal
average signal voltage of the output monitoring signal
by at least 20 decibels over an average signal voltage of
coupled to an associated input, respectively, each feed
back ampli?er amplifying the received signal from the
associated input by a gain of 8 times;
(c) a combiner, operatively coupled to each of the sixteen
average signal voltage of the output monitoring signal
by at least 20 decibels over an average signal voltage of
coupled to an output of the summing circuit which
the combined signal.
13. A combiner-ampli?er, comprising:
(a) sixteen inputs, each input receiving a di?’erent
received signal;
(b) sixteen current feedback ampli?ers, operatively
the frequency band
15. The combiner-ampli?er of claim 13 wherein:
(a) the current feedback ampli?er-based summing circuit
sums the ampli?ed received signals together to form an
intermediate signal;
(b) the combiner comprises a signal splitter, operatively
a current feedback ampli?er which sums the ?rst and
(b) the combiner comprises a signal splitter, operatively
combiner, and the output each manipulate signals between 5
megahertz and 200 megahertz such that the output passes
splitter equally dividing the average signal voltage of the
intermediate signal between the combined signal and the
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output monitoring signal.
17. The combiner-ampli?er of claim 13 further compris
ing a power supply which provides a voltage source to active
circuitry in the sixteen current feedback ampli?ers and the
combiner.
18. The combiner-ampli?er of claim 17 further compris
ing an indicator, operatively coupled to the power supply,
which indicates when the power supply is activated.
current feedback ampli?ers, which combines each of
the ampli?ed received signals together by utilizing a
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