CV111-1 Просмотр технического описания (PDF) - WJ Communications => Triquint

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CV111-1

PCS/DCS-band High Linearity Downconverter

WJ Communications => Triquint 

CV111-1

PCS/DCS-band High Linearity Downconverter

The Communications Edge TM

Product Information

Device Architecture / Application Circuit Information

RF OUT 1

28 27 26

25 24 23 22

IF

21 IF OUT

GND 2 RF Amp

IF Amp 20 GND

N/C 3

19 N/C

GND 4

N/C 5

18 GND

LO Driver Amp

17 BIAS

GND 6

RF

MIXRF 7

8

16 GND

LO

15 LO IN

9 10 11 12 13 14

Typical Downconverter Performance Chain Analysis

Stage

Gain

(dB)

Output

P1dB

(dBm)

Output

IP3

(dBm)

NF

(dB)

Current

(mA)

Cumulative Performance

Gain

(dB)

Output

P1dB

(dBm)

Output

IP3

(dBm)

NF

(dB)

RF Amplifier

13

21

41 3.5 140

13 21.0

41.0 3.5

RF Filter

-2

---

--- 2.0

---

11

19.0

39.0 3.6

LO Amp / MMIC Mixer -9

8

23 9.8

80

2

5.9

22.2 4.7

IF Amplifier

19

23

41 2.1 140

21 20.8

38.1 5.2

CV111-1

Cumulative Performance

360 21.0 20.8

38.1 5.2

RF Amp Bias

RF Bandpass Filter /

Attenuator Pad

RF Amp Matching IF Amp Matching IF Amp Bias

Optional IF

Lowpass Filter

LO Amp Bias

Printed Circuit Board Material:

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

RF / IF Diplexer

(used for cellular versions only)

LO Amp Bias

LO Lowpass Filter

(not used in this product)

CV111-1: The application circuit can be broken up into four main

functions as denoted in the colored dotted areas above: RF/IF

diplexing (purple; this is only used with the cellular-band CV

products), amplifier matching (green), filtering (red), and dc biasing

(blue). There are various placeholders for chip components in the

circuit schematic so that a common PCB can be used for all WJ

single-branch converters. Additional placeholders for other optional

functions such as filtering are also included.

image frequency. It is permissible to not use a filter and use a 2 dB

pad with R6, R7, and R16 instead with slightly degraded noise

figure performance.

External Diplexer: This is only used with the cellular-band CV

products. The mixer performs the diplexing internally for the

CV111-1; therefore the components shown in the diplexer section

should be loaded as follows: C2 = C14 = 0 Ω.

RF / IF Amplifier Matching: The RF amplifier requires a

matching element (C12) for optimal gain and input return loss

performance. 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.

RF Bandpass Filtering: Bandpass filtering is recommended to

achieve the best noise figure performance with the downconverter.

The bandpass filter, implemented with a SAW filter on the

application circuit, allows for the suppression of noise from the

IF and LO Lowpass Filtering (optional): Filtering of unwanted

RF and LO signals are typically performed in the IF chain. This

filtering function may be realized using lumped elements;

placeholders (L9, C21, C22) are provided in the application circuit

to allow for lumped-element filtering to be implemented if desired.

The LO lowpass filter is used only in the cellular-band CV products;

it should not be used for this product. L1 should be loaded with a 0

Ω jumper.

DC biasing: DC bias must be provided for the RF, 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.

This document contains information on a new product.

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

July 2003

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