Split-Mount Microwave Equipment – ODU

Specifications of Transmitter

Working frequency band

Generally, trunk radios use 6, 7, and 8 GHz frequency bands. 11, 13 GHz and

higher frequency bands are used in the access layer (e.g. BTS access).

Output power

The power at the output port of a transmitter. Generally, the output power is 15 to

30 dBm.

Local frequency stability

If the working frequency of the transmitter is unstable, the demodulated effectived

signal ratio will be decreased and the bit error ratio will be increased. The value

range of the local frequency stability is 3 to 10 ppm.

Transmit Frequency Spectrum Frame

The frequency spectrum of the transmitted signal must meet specified

requirements, to avoid occupying too much bandwidth and thus causing too much

interference to adjacent channels. The limitations to frequency spectrum is

called transmit frequency spectrum frame.

lSpecifications of Receiver

Working frequency band

Receivers work together with transmitters. The receiving frequency on the local

station is the transmitting frequency of the same channel on the opposite station.

Local frequency stability

The same as that of transmitters: 3 to 10 ppm

Noise figure

The noise figure of digital microwave receivers is 2.5 dB to 5 dB.

 

Passband

To effectively suppress interference and achieve the best transmission quality, the

passband and amplitude frequency characteristics should be properly chosen. The

receiver passband characteristics depend on the IF filter.

Selectivity

Ability of receivers of suppressing the various interferences outside the passband,

especially the interference from adjacent channels, image interference and the

interference between transmitted and received signals.

Automatic gain control (AGC) range

Automatic control of receiver gain. With this function, input RF signals change within a

certain range and the IF signal level remains unchanges.

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