The Communications Edge TM
CV210-1A
Cellular-band Dual-Branch Downconverter
Product Information
Device Architecture / Application Circuit Information
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Typical Downconverter Performance Chain Analysis (Each Branch)
RF/IF
N/C
GND
BIAS
GND
N/C
1
2
3
4
5
6
7
BIAS
GND
N/C
21
20
19
18
17
16
15
Cumulative Performance
Input
P1dB
(dBm)
Input
IP3
(dBm)
Gain
(dB)
NF
(dB)
Current
(mA)
Input
P1dB
(dBm)
Input
IP3
(dBm)
35.0
29.9
IF Amp 1
Stage
Gain
(dB)
NF
(dB)
GND
LO
LO Amp / MMIC Mixer
IF Amplifier
-8
18
18.5
4.5
35.0
23.5
8.5
2.2
85
150
-8
10
18.5
11.5
8.5
10.5
LPF LO Driver Amp
IF Amp 2
CV210-1A
Cumulative Performance
385*
10
+11.5
+29.9
10.5
GND
N/C
GND
N/C
RF/IF
*
The 2nd branch includes another mixer and IF amplifier, which increases the total current consumption
of the MCM to be 385 mA.
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Printed Circuit Board Material:
.014” FR-4, 4 layers, .062” total thickness
CV210-1A: The application circuit can be broken up into three main
functions as denoted in the colored dotted areas above: RF/IF diplexing
(blue), IF amplifier matching (green), and dc biasing (purple). There are
various placeholders for chip components in the circuit schematic so that
a common PCB can be used for all WJ dual-branch converters. Further
details are given in the Application Note located on the website titled
“CV2xx Series - PWB Design Guidelines”.
IF Amplifier Matching: The IF amplifier requires matching
elements to optimize the performance of the amplifier to the desired
IF center frequency. Since IF bandwidths are typically on the order
of 5 to 10%, a simple two element matching network, in the form of
either a high-pass or low-pass filter structure, is sufficient to match
the MMIC IF amplifier over these narrow bandwidths. Proper
component values for other IF center frequencies can be provided by
emailing to applications.engineering@wj.com.
External Diplexer: In a downconversion application, the incoming RF
signal impinges on the switching elements of the mixer; the interaction
with these switches produces a signal at the IF frequency. The two
signals (RF and IF) are directed to the appropriate ports by the external
diplexer. A six-element diplexer is used in the circuit implementation.
DC biasing: DC bias must be provided for the LO and IF amplifiers
in the converter. R1 sets the operating current for the last stage of the
LO amplifier and is chosen to optimize the mixer LO drive level.
Proper RF chokes and bypass capacitors are chosen for proper
amplifier biasing at the intended frequency of operation. The “+5 V”
dc bias should be supplied directly from a voltage regulator.
Specifications and information are subject to change without notice
WJ Communications, Inc • Phone 1-800-WJ1-4401 • FAX: 408-577-6621 • e-mail: sales@wj.com • Web site: www.wj..com
Page 2 of 6 January 2006
WJCI [ WJ COMMUNICATION. INC. ]
