User Guide

PAMS Technical Documentation System Module
NSB-5
Issue 1 03/01 Nokia Mobile Phones Ltd. Page 67
First IF Filter
The first IF filter is a SAW filter to improve the blocking conditions caused by inband spu-
rious signals which cause a noise rice effect in second mixer if looser filter is used.
Table 22: First IF filter specifications
Second Mixer (VHF) in CRFU_2a
Second mixer is double balanced common emitter Gilbert cell. The mixer is optimized for
differential drive; however, it can also be used with single ended drive. The LO-port is AC
coupled internally.
Table 23: Second mixer specifications
Parameter Minimum
Typical/
Nominal
Maximum Unit/Notes
Operating temperature range -30 ... +85 deg. C
Center frequency, fo 487 MHz
Maximum Ins. loss at 1dB BW 3.0 4.5 dB
Group delay ripple at 1dB BW 1.0 us pp
Bandwidth relative to fo
1dB bandwidth
10 dB bandwidth
13dB bandwidth
20 dB bandwidth
25 dB bandwidth
30 dB bandwidth
+/-200 +/-600
+/-800
+/-1000
+/-1600
+/-3000
kHz
kHz
kHz
kHz
kHz
kHz
Spurious rejection, fo +/->5MHz 35 dB
Terminating impedance (balanced)
input
output
240//-0.4
330//-0.2
ohms//pF
ohms//pF
Package size
length x width (max)
height (max)
3.8 x 3.8
1.8
mm
mm
Assembly SMD Reflow
Parameter Minimum
Typical/
Nominal
Maximum Unit/Notes
Input frequency 487 MHz
Output IF frequency 87 MHz
Input LO frequency 400 MHz
Input LO level 200 600 mVpp
LO input resistance 200 ohms/at400MHz