A phased array using sub-array techniques

Abstract

Each radiating element shifter; t h e p h a s e i s changed f o r e a c h beam p o s i t i o n . A m u l t ip l i c i t y o f r a d i a t i n g e l e m e n t s i s combined i n t o a sub-array. Transmitting and receiving amplification, separated by s u i t a b l e T-R d e v i c e s , t a k e s p l a c e a t t n e s u b -a r r a y l e v e l . F o r broad-band operation, time-delay, rather th&n phase, i s adjusted for each a p p r o p r i a t e m e l e n g t h s i n t o t h e c i r c u i t . The r e s u l t m t band-sub-array. This can be achieved, for example, by switching w i d t h in percent then approximately equals numerically the suba r r a y beamwidth i n degrees. The required combining network may For t h e r e c e i v e r , a somevrnat more complex network i s d e s i r a b l e amount t o an equi-phase and equj-power d i v i d e r f o r the transn-&tter. giving separately optimized sum and d i f f e r e n c e p a t t e r n s . S U B -m Y A 48-element sub-array has been developed a t C-band. Power i s s p l i t 4-ways i n the H-plane t o f o u r a d j a c e n t E -p l a n e s e c t o r a l horns as shown i n Figure 2. This method of power d i v i d i n g g i v e s a' constant amplitude distribution across the sub-array. In an array of sub-arrays, t h i s constant amplitude distribution i s i s placed i n t h e mouth of each horn t o c o r r e c t t h e i n h e r e n t required t o suppress grating lobes. A matched d i e l e c t r i c l e n s 1 2 waveguides arranged as shown i n Figure 3. The w a v e m d e s , s p h e r i c a l p h a s e f r o n t . Eacn of t n e f o u r s e c t o r a l h o r n s f e e d s 98

A calculation technique of multi-beam directions for emitter detection

“…However, on a case of an emitter is moving, the directions cannot decide before the operation. Other side, a sub-array DBF method [2] is often used for a minimization of the DBF system. The sub-array DBF method consists of an analog processing and a digital processing.…”