Circuit separates out, from multiplied signals, antenna element signals which have desirable phase angles and feeds them to appropriate antenna elements of phased array. System may be used in either transmitting or receiving mode

Caron, P. R.

Mailloux, R. J.

English

NASA Technical Reports Server

Jantiary 1975	 B74-10251 
NASA TECH BRIEF 
NASA Pasadena Office 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Phased-Array Antenna Phase Control Circuit Using Frequency Multiplication 
.
The problem: 
Phase control of a phased-array antenna is 
normally accomplished by an antenna coupling 
circuit. Thus a transmitter or a receiver, depending on 
whether the system is transmitting or receiving, is 
coupled to the antenna elements of the phased array 
through a power-dividing chain which has phase-
shifting elements connected at some point or points in 
it. For instance, some previous phase controllers 
employ phase shifters connected at the ends of the 
power-dividing chains just prior to their connections 
with the antenna elements. Others have the phase 
shifters connected in series along the power divider 
chains. The major problem with such phase control 
circuits is that they are not accurate enough. 
More-sophisticated phase control circuits are capable 
of relatively-accurate phase control; however, in 
general they require expensive and nonstandard 
components. 
Terminating	 0	 8	 28 Resistor
The solution: 
A new phase control coupling circuit uses frequency 
multipliers. The circuit separates out, from these 
multiplied signals, antenna element signals which 
have desirable phase angles and feeds them to the 
appropriate antenna elements of the phased array. 
The system may be used in either a transmitting or a 
receiving mode. 
How it's done: 
A frequency-doubling phase control circuit is 
illustrated in the figure. A signal supplied by the 
transmitter passes through the two-way power divider 
and the phase shifter to terminals 0 and 0. Thus a 
signal (2S) which has zero relative phase shift 
appears at terminal 0, and a signal (2S 2) with a 
relative phase shift of 00 appears at terminal 0. 
Assuming a pure sine wave signal, these signals are 
given by
2S1 = 2 cos vt 
-	 +1	 JT_	 +1	 I-	 and 
tat 2nd	 3rd 
180 .
 Hybrid	 t80 Hybrid	 t80 Hybrk 
Sum-and-	 Sum-and-	 Sum-and- 
Difference	 Difference	 Difference 
Network	 Network	 Network
having input-to-output amplitude ratios of 2. Thus 
the outputs of these dividers are S and S21 
respectively. One four-way power divider connects 
signals S 1 to the first and second inputs of a 
Sr	
S	
combining 1800 hybrid sum-and-difference network 
Four-way	 and to the first input of a second such network. P
ower Divider Signals S 2 are connected similarly to the second input 
of the second network and to the first and second 
inputs of a third 180° hybrid (see figure). The fourth 
output of each power divider is connected to other 
hybrids which, for simplicity, are not shown. 
1	 I-	 °I	 I—  
 
Surmr-afld-	 I	 Sum-and- 
180	 Hybrid	 I	 I	 t80	 Hybri
Difference	 Difference 
4st I 	 2nd	 I	 1	 3rd 
Network	 I	 Network 
s 	 s,	 s,	 ¶s, 
Power Divider 	 I	 Power Four-way	 ?25	 Two-way	
2SI Divider Phase	 I 
Shifter	 I 
a')	 J	 e 
is
Transmitter 
Doubler Phase Control Circuit
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United Stales 
Government nor any person acting on behalf of the United States
(continued overleaf) 
Recombining	 2S2 = 2 cos (cot+O) 
Networks	 where t denotes time in seconds, co is the angular 
velocity of the signals, and 0 is the angle by which S2 
52 Frequency	 leads S1. 
Doubters	 Each signal is fed to a four-way power divider 
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights. 
https://ntrs.nasa.gov/search.jsp?R=19740000251 2020-03-17T13:59:15+00:00Z
The combining hybrids each have a sum port and a 
difference port. Thus the sum signal from the second 
180 0
 hybrid is given by (S1+S2)//2, and the dif-
ference signal is given by (S1—S2)//2. 
The sum-and-difference ports of each hybrid are 
connected to frequency doublers, the outputs of which 
are proportional to the square of their inputs. The 
doublers connected to the second hybrid, for example, 
have the outputs (S 1 +S) 2/2 and (Sr—S02 /2. Finally, 
the sum-and-difference frequency doublers of the first 
180° hybrid are connected to the first and second 
inputs of the first recombining 180° hybrid network, 
those of the second hybrid are connected to the inputs 
of a second recombining network, and those of the 
third hybrid are connected to the inputs of a third 
recombining network. 
The difference ports of the three recombining 
networks feed active antenna elements, while the sum 
ports are applied to terminating resistors. The outputs 
at the difference ports of the three recombining 
networks are proportional to 
12 S 1S 1,	 (1st) 
[2 S 1S 2,	 (2nd), and 
12 S 2S 2;	 (3rd) 
corresponding to signals given by 
(1//2) cos (2cot), 
(1//2) cos (2cot+O), and 
( 11 [2) cos (2wt+20). 
Thus the doubler phase control coupler circuit 
provides three outputs, each having a frequency of 
2ot, which is double the frequency of the input signals 
S 1 and S 2. The first output signal has a zero relative 
phase shift, the second has a relative phase shift of 0, 
and the third has a relative phase shift of 20.
A unique feature of the doubler phase control 
circuit is that it may be used even when the frequency 
doubler conversion loss is a variable function of the 
power input. Thus the doubler phase control circuit 
yields phase-shifted signals which are shifted one from 
the other by highly accurate increments. Moreover, 
the circuit employs standard, interchangeable compo-
nents and is relatively uncomplicated. Finally, the 
principle of the doubler phase control circuit may also 
be used for more generalized phase control circuits 
which use higher orders of multiplication to produce a 
greater number of phase-shifted output signals. 
Note: 
Requests for further information may be directed 
to:
Technology Utilization Officer 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Reference: TSP74-10251 
Patent status: 
This invention has been patented by NASA (U.S. 
Patent No. 3,710,329). Inquiries concerning nonex-
clusive or exclusive license for its commercial develop-
ment should be addressed to: 
Patent Counsel 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Source: Robert J. Mailloux and 
Paul R. Caron

Electronics Research Center
(ERC- 10285)
. 
Categories: 01 (Electronics - Components and 
Circuitry) 
02 (Electronics Systems) B74-10251


Phased-array antenna phase control circuit using frequency multiplication

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