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S e m i c o n d u c t o r R e s e a r c h Lab., C l a r i o n C o . , L t d . , K a n a y a , Koriyama, R e s e a r c h I n s t i t u t e o f E l e c t r i c a l Communication, Tohoku U n i v e r s i t y , : :*,Fukushima 963-07, J a p a n K a t a h i r a , S e n d a i 980, J a p a n A b s t r a c t W e h a v e f a b r i c a t e d a m o n o l i t h i c ZnO/SiO,/Si Sezawa wave c o n v o l v e r w i t h t h e BT p r o d u c t a s h i g h as 210. A programmable SAW c o r r e l a t o r u s i n g t h e c o n v o l v e r h a s been o b t a i n e d . The c h a r a c t e r i s t i c s o f t h e c o n v o l v e r are a s f o l 1 o w s : t o t a l g a t e l e n g t h = 40 mm, g a t e delay time= 9 U S , i n p u t c e n t e r f r e -quency= 210 MHz, o u t p u t c e n t e r f r e q u e n c y = 420 MHz, 3dB bandwidth= 23.4 MHz, t e r m i n a l e f f i c i e n c y ( F )--52.1 dBm, dynamic r a n g e a b o v e t h e r m a l n o i s e f T o o r = 52 dB, s e l f -c o n v o l u t i o n s p u r i o u s l e v e l = -35 dB. T h e g a t e o f t h e c o n v o l v e r i s s e p a r a t e d i n t o two p a r t s f o r DPSK ( d i f f e r e n t i a l p h a s e s h i f t k e y i n g ) d e m o d u l a t i o n . The dynamic r a n g e o f t h e c o r r e l a t i o n peak f o r a 63 c h i p s M(Maxima1)-sequence PN ( p s e u d o n o i s e ) c o d e is 4 6 . 5 dB. W e h a v e o b t a i n d DPSK demodu l a t i o n s i g n a l s f o r 31x2 and 63x2 c h i p s s e q u e n c e s . 1. I n t r o d u c t i o n A o n o l i t h i c ZnO/SiO / S i Sezawa wave c o n v o l -2 v e r ')-" h a s some p o t e n t i a l a d v a n t a g e s : ( 1 ) t h e i n p u t power c a n be r e d u c e d b e c a u s e o f t h e h i g h e f f i c i e n c y , ( 2 ) t h e dynamic r a n g e a b o v e t h e r m a l n o i s e f l o o r i s l a r g e compared w i t h t h e o t h e r t y p e s o f c o n v o l v e r s w i t h t h e same bandwidth-time (BT) p r o d u c t b e c a u s e o f t h e h i g h e f f i c i e n c y a n d t h e a p p r o p r i a t e s a t u r a t i o n l e v e l , ( 3 ) i t w i l l b e i n t eg r a t e d w i t h a s i l i c o n I C . I n a p r e v i o u s p a p e r , w e had r e p o r t e d a Sezawa wave c o n v o l v e r w i t h t h e BT 3 ) p r o d u c t of 1 0 2 whose v a l u e h a s been t h e l a r g e s t o n e u n t i l now i n t h e case o f Sezawa wave c o n v o l v e r . I n t h i s r e p o r t , w e d e s c r i b e t h e f o l l o w i n g s u b j e c t s : ( 1 ) t h e s p e c i f i c a t i o n a n d t h e f a b r i c a t i o n o f a ZnO/ S i 0 2 / S i Sezawa wave c o n v o l v e r w i t h t h e BT p r o d u c t o f 210, ( 2 ) t h e c h a r a c t e r i s t i c s o f t h e programmable SAW c o r r e l a t o r , (3) t h e DPSK d e m o d u l a t i o n c h a r a c t e w e h a v e made a s p e c i f i c a t i o n o f a new c o n v o l v e r w i t h t h e g a t e l e n g t h o f 40mm, t h e c e n t e r f r e q u e n c y o f 210 MHz, a n d t h e BT p r o d u c t o f 210. The g a t e e l e c t r o d e i s s e p a r a t e d i n t o two p a r t s i n o r d e r t o d...

A theory for the propagation loss of surface acoustic waves on a monolithic metal-insulator-semiconductor structure is developed. We derive the theory for the case where an epitaxial layer of semiconductor on a heavily doped substrate is used. The experimental results obtained by using Sezawa waves on a monolithic ZnO/SiO2/Si structure are compared with the theoretical predictions. The theoretical values are in good agreement with the experimental values in regard to the bias-voltage characteristics, the temperature characteristics, and the effects of the impurity concentration and the thickness of the epitaxial layer. It is shown that the surface-acoustic-wave propagation loss is considerably sensitive not only to the impurity concentration but also to the thickness of the epitaxial layer.