Page 406 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim
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386 IDT MICROSENSORS
( 3 ) Electrical
o
Acoustic
Acoustic
O ©
IHHUl SAW
SAW vr.
Figure 13.22 Schematic representation of electrical and acoustic ports
where
+ Z e )] + Z e)]
(R s a (R s
exp((0ti
i + 0 i J
t = e (13.69)
—s —— — s\l — — exp(—0 t i) J
L l+0 e i J L l+0 e i J
with 0 e = (wC t + B a)(R s + Z e) and 0 t = N t
-exp(0 ti/2)
1 -r-tv
T = (13.70)
L
1 + 0 ei
T. = (13.71)
1+0 e i
where GO = k 2 • C s • f 0 is the characteristic radiation conductance and
- 2sin(0,/2) 2
G a = G 0(N, — I) 2 if w = w 0; else G a = G 0(N t — 1) 2 ' 2 (13.72)
2sin(0 t) —0 t
2
2
B a = 0 if w = w 0; else B a = 2G 0 (N t — 1) A (13.73)
2
0 t
(13.74)
6 C = wC t (R s + Ze) (13.75)
k 12
c
C = — osh(L) (13.76)
a
