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 March 2006

CV210-2A

Cellular-band Dual-Branch Downconverter

Product Information

The Communications Edge

TM

Device Architecture / Application Circuit Information

Typical Downconverter Performance Chain Analysis (Each Branch)

Cumulative Performance

Stage

Gain

(dB)

Input

P1dB

(dBm)

Input

IP3

(dBm)

NF

(dB)

Current

(mA)

Gain

(dB)

Input

P1dB

(dBm)

Input

IP3

(dBm)

NF

(dB)

LO Amp / MMIC Mixer

-9

11

30

9.3

85

-9

11

30

9.3

IF Amplifier

19

2

22

1.8

150

10

8

27.5

11

CV210-2A

Cumulative Performance

385*

10

+8

+27.5

11

*

The 2

of the MCM to be 385 mA.

CV210-2A: 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”.

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.

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.

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.

Printed Circuit Board Material:

.014” FR-4, 4 layers, .062” total thickness

1

2

3

4

5

6

7

21

20

19

18

17

16

15

28

27

26

25

24

23

22

8

9

10

11

12

13

14

IF Amp 2

IF Amp 1

LO Driver Amp

BIAS

GND

N/C

GND

LO

GND

N/C

N/C

GND

BIAS

GND

N/C

GND

N/C

RF/IF

RF/IF

LPF