cv110-2a WJ Communications, Inc., cv110-2a Datasheet - Page 2

• Manufacturer Part Number: cv110-2a
• Description: Cellular-band High Linearity Downconverter
• Manufacturer: WJ Communications, Inc.

CV110-2A: The application circuit can be broken up into four main
functions as denoted in the colored dotted areas above: RF/IF
diplexing (purple), 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.
RF / IF Amplifier Matching:
matching element 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
[e-mail].
RF Bandpass Filtering:
reject the image frequencies and achieve the best noise figure
WJ Communications, Inc • Phone 1-800-WJ1-4401 • FAX: [phone] • e-mail: [e-mail] • Web site: www.wj.com , www.TriQuint.com
IF THRU
RF OUT
RF/IF
GND
GND
GND
N/C
1
2
3
4
5
6
7
RF/IF
RF Amp
RF Bandpass Filter /
28
8
Attenuator Pad
CV110-2A
Cellular-band High Linearity Downconverter
IF Feedthru
27
9
Path
(used for cellular versions only)
26
10
Device Architecture / Application Circuit Information
25
11
RF / IF Diplexer
LO
RF Amp Bias
24
12
LO Driver Amp
Bandpass filtering is recommended to
23
13
IF Amp
22
14
The RF amplifier requires a shunt
RF Amp Matching
21
20
19
18
17
16
15
IF OUT
GND
N/C
GND
BIAS
GND
LO IN
MMIC Mixer
RF Amplifier
IF Amplifier
CV110-2A
RF Filter
IF Amp Matching
Stage
Frequency (MHz)
R8 (ohms)
C17 (pF)
L7 (nH)
L4 (nH)
IF Amplifier Matching
LO Amp Bias
Gain
(dB)
13.5
-9.0
19.0
-1.5
IF Amp Bias
Typical Downconverter Performance Chain Analysis
Cumulative Performance
LO Amp Bias
Output
(dBm)
P1dB
180
330
21
---
22
4.7
2.2
performance with the downconverter.
implemented with a SAW filter on the application circuit, allows for
the suppression of noise from the 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.
evaluation boards will have the 2 dB pad in place.
External Diplexer:
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. Pin 5 contains the IF signal and allows the
signal to be transferred to pin 25 for the convenience of PCB layouts.
DC biasing:
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.
82
8
210
220
3.3
2.2
Output
82
(dBm)
40.0
23.0
39.1
IP3
---
Printed Circuit Board Material:
.014” FR-4, 4 layers, .062” total thickness
240
220
3.9
2.2
56
DC bias must be provided for the RF, LO and IF
(dB)
NF
3.5
1.5
9.8
2.5
Specifications and information are subject to change without notice
In a downconversion application, the incoming
Current
(mA)
150
150
360
60
---
Gain
(dB)
22.0
22.0
13.5
12.0
3.0
Cumulative Performance
Output
(dBm)
P1dB
21.0
20.3
20.3
19.5
6.1
The bandpass filter,
Page 2 of 4 April 2007
Output
(dBm)
40.0
38.5
22.1
37.0
37.0
IP3
Standard WJ
(dB)
NF
3.5
3.5
4.5
5.0
5.0