User's Manual

Two Channel 400MHz Cell Enhancer

User Handbook

Handbook N.-50-128501HBK Issue No:-A

Date:-12/08/2005

Page:-

18 of 39

4.2 Bandpass Filters (02-011204 & 02-013401)

4.2.1 Description

The bandpass filters are multi-section designs with a bandwidth dependent upon the passband

frequencies, (both tuned to customer requirements). The response shape is basically Chebyshev

with a passband design ripple of 0.1dB. The filters are of combline design, and are carefully

aligned during manufacture in order to optimise the insertion loss, VSWR and intermodulation

characteristics of the unit. The tuned elements are silver-plated to reduce surface ohmic losses

and maintain a good VSWR figure and 50 load at the input and output ports.

Being passive devices, the bandpass filters should have an extremely long operational life and

require no maintenance. Should a filter be suspect, it is usually most time efficient to replace

the module rather than attempt repair or re-tuning.

4.2.2 Technical Specification

FILTER 1 489.5-491 MHz (02-011204)

FILTER 2 496.3-496.7 MHz (02-013401)

FILTER 3 492.5-494 MHz (02-011204)

Passband:

FILTER 3 499.3-499.7 MHz (02-013401)

FILTER 1 3.0 dB (02-011204)

FILTER 2 3.5 dB (02-013401)

FILTER 3 3.0 dB (02-011204)

Insertion Loss:

FILTER 3 3.5 dB (02-013401)

FILTER 1 MAX(>40dB) (02-011204)

FILTER 2 MAX (>40dB) (02-013401)

FILTER 3 MAX (>40dB) (02-011204)

Isolation:

FILTER 4 MAX (>40dB) (02-013401)

Impedance: 50 ohm