The model development of residual BER focuses primarily on the source's phase noise and the power amplifier AM/PM distortion, These key components usually represent the greater part of the residual error budget and are often responsible for the vast majority of the cost of the radio, There are other secondary contributors to the error floor, including group delay distortion
or inter symbol interference (ISI).
These functions range from communications to radar, as evidenced by requirements for low phase noise, low group delay distortion
, wide instantaneous bandwidths (0.5 to 2 GHz are common) and fast tuning speed in one tuner.
The series include low-pass, high-pass, band-reject and bandpass filters, and can also be used as delay lines, with desirable control of group delay distortion
. Trilithic Inc.
(sometimes called inter-symbol interference (ISI)) causes the symbol point to be distorted based on the previous symbol point.
A non-linear phase response will cause group delay distortion
, introducing data-dependent jitter or intersymbol interference into the data stream.
Group delay distortion
also may be introduced into the FFA system because the varactors resonate to change their phase.
The problem with this approach is the introduction of group delay distortion
. Ideally, the phase shifter should have a linear phase vs.
The effect of group delay distortion
on a quadrature phase-shift keying (QPSK) digital transceiver is considered.
Also incorporated into the design are multisection group delay equalizers that minimize the effects of group delay distortion
The IF filter for both systems is required to have 200 kHz of band-width, low insertion loss and low group delay distortion
. A new low loss filter design technique has been applied to address the requirements of this rapidly developing market.
This test translator is said to deliver reliable translations with a minimum of amplitude and delay distortions
. Functional specifications include -90 dBc at 10 kHz offset, -100 dBc at 100 kHz offset, band select switch, local attenuator adjust, lock alarm indicator, RS-485 address switch, RS-485 for attenuator control and band select.