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Many r a d a r and communication a p p l i c a t i o n s r e q u i r e phased a r r a y elements h a v i n g dual p o l a r i z a t i o n . Where t h e r e i s a requirement f o r low p r o f i l e and/or c o n f o r m a l i t y , t h e m i c r o s t r i p patch radiat o r becomes a prime candidate. Described h e r e i n i s a well-matched m i c r o s t r i p patch r a d i a t o r havi n g orthogonal d u a l -l i n e a r p o l a r i z a t i o n . T h i s i s accomplished over a wide bandwidth and wide scan angle under a l o w -p r o f i l e c o n s t r a i n t . VSWR o v e r a 10% bandwidth and suppression o f cross p o l a r i z a t i o n by more than 20 dB. u r a t i o n are as f o l l o w s ; orthogonal balanced probe feeds, one p a i r connected t o t h e base p l a t e ( h o r i z o n t a l p o l a r i z a t i o n ) and t h e o t h e r connected t o t h e patch ( v e r t i c a l p o l a r i z a t i o n ) , as shown i n Fig. 1; a m i c r o s t r i p matching c i r c u i t , as represented by t h e schematic i n Fig. 2; and t h e topology which permits both p o l a r i z a t i o n matching c i r c u i t s t o c o -e x i s t i n one s t r u c t u r e . Both l i n e a r p o l a r i z a t i o n implementations were determined by a r i g o r o u s numerical computer code [4], [3] and employ a doubletuned broadband-matching technique [2]. The design was v e r if i e d u s i n g an i n f i n i t e -a r r a y waveguide s i m u l a t o r [l] and t h e performance evaluated by s m a l l l a r r a y mutual c o u p l i n g and patt e r n measurements. Computer-aided design.techniques have been a p p l i e d t o t h e l a y o u t , photo exposure, e t c h i n g and d r i l l i n g o f t h e m i c r o s t r i p -p a t c h p r i n t e d -c i r c u i t matching networks. The d u a l -p o l a r i z e d patch r a d i a t o r c o n s i s t s o f a conducting patch over t h r e e l a y e r s o f d i e l e c t r i c (E,. = 2.2) and a p a i r o f balanced probe feeds. t y p e connector and a 50 ohm m i c r o s t r i p l i n e i n t o a r e a c t i v e s p l i t t e r . An o p e n -c i r c u i t e d stub i s used t o double-tune t h e patch resonant c i r c u i t response. The r a d i a t o r c o n s i s t s o f a < 0.10 wavelength t h i c k d i e l e c t r i c l a y e r sandwiched between two t h i n d i e l e c t r i c layers. The patch i s etched on t h e t o p s i d e o f t h e t h i n t o p l a y e r ; t h e h o r i z o n t a l p o l a r i z a t i o n balun i s etched on t h e bottom s i d e o f t h i s l a y e r . The v e r t i c a l p o l a r i z a t i o n balun i s etched on t h e bottom s i d e o f t h e t h i c k l a y e r separated from t h e ground p l a t e by t h e o t h e r t h i n l a y e r . The patch i s used as t h e ground plane f o r t h e h o r iz o n t a l p o l a r i z a t i o n balun and t h e bottom p l a t e t h e r e t u r n f o r t h e v e r t i c a l p o l a r i z a t i o n balun. The probes f o r t h e h o r i z o n t a l p o l a r i z a t i o n are i s o l a t e d from t h e patch u s i n g a p l a t...

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An echo sounder and a water thermometer are combined in this apparatus to help a fisherman find good fishing grounds. The echo sounder has a conventional depth indicator in which a lamp is carried on a disk that rotates at constant speed. When an echo is received, the lamp flashes to indicate the depth by its position at the instant when the flash occurs. When the apparatus is switched to measure temperature, a thermistor senses the temperature of the water, and the same revolving lamp indicates the result. The thermistor varies the time constant of an RC circuit according to the temperature, and that circuit causes a flip-flop circuit to illuminate the lamp for a corresponding time. The moving lamp traces an arc of light whose length indicates the temperature. Unfortunately, the thermistor is situated within the transducer housing that is mounted on the vessel's hull. Consequently, it measures the temperature of the water near the surface, and not that of the deeper and colder water where most fish prefer to live.-LB 4,115,753 43.30.Yj FIBER OPTIC ACOUSTIC ARRAY

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