CHM2179B98F_15 Datasheet, PDF (5/8 Pages) United Monolithic Semiconductors – W-band Mixer

W-Band Mixer
CHM2179b98F
Typical Bias and IF Configuration
Several external configurations are possible for bias and IF. The objective is to give flexibility
for the integration.
As this component is mainly dedicated to low IF use, there are several possibilities for
interfacing with low noise IF amplifier. The optimum IF load for conversion loss is 200,
however depending on the IF amplifier noise characteristic this load can be modified in order
to optimise the noise figure. A series capacitor, between IF output and the load is
recommended.
Due to high sensitivity to electrical discharges an integrated resistance is used and two ports
are available for biasing. One is for the connection of a decoupling capacitor (C_ext) and the
other one is for the supply voltage connection through an external series resistance (+V port).
However, in order to keep the compatibility with the CHM2179b98F, only the “C_ext” port can
be used.
C_bias
C_ext
LO
+V
R_bias1
+V
1k
R_load_IF
C_IF
IF
RF
+V
C_bias
R_bias2
C_ext
+V
1k
LO
R_load_IF
C_IF
IF
RF
Recommended external bias and IF
configuration
Other possible configuration
(compatible with the previous version)
The recommended values for external components are:
C_bias
R_bias x C >> 1/F_IF
R_bias1
2.9k for 1mA current consumption (V = 4.5V, typical LO power)
R_bias2
R_bias2 = R_bias1 + 1k
R_load_IF
From 50 to 200
Notes:
(1) _{R_bias = R_bias1 + 1k when “+V” port is used, otherwise R_bias = R_bias2. R_bias can}
be adjusted if necessary; this allows optimizing the performances when some parameters are
different from recommended ones (Supply voltage, LO power …). However maximum ratings
for the current have to be taken into account.
(2) _{A series capacitor at IF outputs is recommended for DC decoupling.}
Ref. : DSCHM2179b98F3246 - 03 Sep 13
5/8
Specifications subject to change without notice
Bât. Charmille - Parc SILIC - 10, Avenue du Québec - 91140 VILLEBON-SUR-YVETTE - France
Tel.: [phone] - Fax: [phone]