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 3 of 9 June 2007

CV211-2A

UMTS/WiMax-band Dual-Branch Downconverter

Product Information

The Communications Edge

TM

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.

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.

Application Circuit: IF = 75 MHz (CV211-2APCB75)

RF = 1900 – 2700 MHz, IF = 75 MHz

PCB Layout

Circuit Board Material: .014” FR-4, 4 layers, .062” total thickness

Bill of Materials

Ref. Desig.

Component

Size

R1

11.3 Ω chip resistor

0805

R2, R3, R4, L3, L7

L10, L11

0 Ω chip resistor

0603

R6, R7

3.3 Ω chip resistor

0603

C1, C5, C10, C15

1000 pF chip capacitor

0603

C4, C11

22 pF chip capacitor

0603

C6, C12, C14

.018 µF chip capacitor

0603

C7, C13

100 pF chip capacitor

0603

L1

120 nH chip inductor

0603

L4, L8

150 nH chip inductor

0603

L5, L9

220 nH chip inductor

0805

C2, C3, C8, C9, C16

C17, C19, C20, C21

C22, L2, L6

Shown on silkscreen, but

not used in actual circuit.

U1

CV211-2A WJ Converter

QFN