U2796B Datasheet, PDF (9/11 Pages) TEMIC Semiconductors – 2-GHz Single Balanced Mixer

Application Circuit
C1
LOi
93 7765 e
876
U 2796 B
5
IFO
Cr
N
IFout
U2796B
12
C2
IFO
34
C3
R2
RFi
RIP3
C4
VS
Figure 12.
Recommended Values for the Evaluator
C₁ and C₂ = 150 pF, C₃ and C₄ = 100 nF. C_r is calculated
u ^{for resonance with the balun at fIF, or as a high pass filter}
for f_LO. The output balun transformer ratio = 8:1 for Z_O
= 50 Ω. R₂ increases the IF output level and is calculated
from:
W impedance of a subsequent filter is 1 k , the capacitive
voltage divider may be left out.
V_S
V_S
95 9632
+ R₂
V_S (4, 5) – V_S (1)
I_S (1)
L₁
L₂
C₂
[ ^{For example VS (4,5) = 4 V, VS (1) = 3 V, IS (1) = 2.2 mA}
R₂ 470 Ω, where I_S (1) is the current consumption with-
out the mixer stage.
C₁
4
5
C₂ R
Application Hint
The output transformer at the pins 4 and 5 can be replaced
by LC-circuits like one of the following proposals, which
are saving space compared to the transformer and are suit-
able for higher IF frequencies. When applying one of
these solutions, it has to be checked whether the require-
ments on noise figure and gain can be achieved.
W ^{The second circuit was dimensioned for approximately}
130 MHz and a load resistance of 50 . If for instance the
V_S
1 mH
8.2 pF
4
10 pF
220 nH
5
Figure 13.
R_L = 50 W
39 pF
Rev. A2, 15-Oct-98
9 (11)
Preliminary Information