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Specifying Lowpass Filters

Lowpass Filter Part Number Description

Cavity Filter Part Number Description


1. Number of Sections

2. Series and Package Size

3. Center Frequency (3 dB C/O Standard)

4. Input Connector

5. Output Connector (if different from Input)

(1) 6" RG 188 Standard
(2) Requires SMA Removable Connectors at High Frequencies

The curve shown indicates the frequency response resulting from the circuit used.

Bandwidth Designator
3 dB /(blank)
1 dB /A
equi-ripple /R
special /X
Connectors
Connector Type Designator
Blind Mate BP
Cable (1) C
RF Pin (2) P
SMA Female S
SMA Male SM
SMB Female SB
SMC Female SC
SMA Removable SR
Surface Mount M
Surface Mount Pins MP
Special X
Overview
Bandpass
Lowpass
Highpass
Charts

 

Example:
A LP-Series filter has a cutoff frequency of 1000 MHz. A stopband attenuation of 30 dB is required at 1250 MHz.

Calculate the number of sections as follows:

Example 1

Number of 3 dB bandwidths from cutoff frequency = The curve indicates that a minimum of 5 sections is required.

Insertion Loss Calculation
Knowing the number of sections, and cutoff frequency of the filter, insertion loss may be calculated from the following formula:

Loss = N x 0.2

Example: 7LP7 - 1275 - S
1. Number of sections = 7
2. IL = 7 x 0.2 = 1.4 dB

Note: For Lowpass filters, insertion loss is calculated at 0.9 times the cutoff frequency

Lowpass Attenuation Chart


Discrete Component Lowpass Filters
P/N  Freq. Range
(MHz)
VSWR
(Nominal)
Number of
Sections
Avg. Power
(Watts)
Operating
Temp. (Deg. C)
Relative
Humidity
LP2 1 - 100 1.5:1 2 - 10 10 -55 to +85 95%
LP3 2.5 - 150 1.5:1 2 - 10 10 -55 to +85 95%
LP4 10 - 200 1.5:1 2 - 10 10 -55 to +85 95%
LP5 0.1 - 10 1.5:1 2 - 10 10 -55 to +85 95%
LP6 10 - 6000 1.5:1 2 - 10 1 -55 to +85 95%
LP7 10 - 6000 1.5:1 2 - 10 1 -55 to +85 95%
LP8 10 - 6000 1.5:1 2 - 10 1 -55 to +85 95%
LP9 10 - 6000 1.5:1 2 - 8 1 -55 to +85 95%
T8L 70 - 1000 1.5:1 2 - 4 1 -55 to +85 95%

Shock 10G
Vibration 20G
See Charts page for outlines and dimensions.
Contact factory for specific requirements not listed above.

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