TETRA Antenna Combiner

Operate up to 4 TETRA radios through a single antenna

The TETRA Antenna Combiner works in conjunction with the Gemini survey tool to allow up to 4 TETRA class 3 (3W) radio terminals to be connected to a single antenna whilst meeting all ETSI requirements for intermodulation products. The Combiner includes an ultra-linear wide-band TETRA amplifier to compensate for combining losses as well as specially designed receiver amplifiers to eliminate wide-band noise interference between terminals, thereby ensuring that there is absolutely no reduction in performance for any radio terminal.

Two models are available:

Model A – Up to two class 3 radio terminals may be configured for 0dB gain whilst the other two radio terminals must operate with 11dB loss.

Model B – Up to two class 3 radio terminals may be configured for 0dB gain whilst the other two radio terminals must operate with 11dB loss.

Terminals with 11dB loss simulate the performance of a hand-portable antenna and further attenuation of 5dB or 15dB may be added to simulate building losses. The combiner also includes a switch to insert a further 5dB attenuation into the transmit path to simulate the transmit power of a class 4 (1W) hand-portable.

  • Reduces network survey time by operating up to 4 different radio terminals simultaneously
  • Inherently adaptable allowing many different configurations
  • Single antenna ensures that all radio terminals have the ideal radiation pattern
  • Provides high levels of isolation between terminals with no degradation of signal

Frequency:                    Tx 380-385MHz
Rx 390-395MHz

Tx Insertion Loss:        Model A: Ports 1 & 2: 0dB
Ports 3 & 4: 11dB
Model B: All Ports: 11dB

Rx Gain:                        Configured to be identical to Tx path loss for each port

Port to Port Isolation (Tx Band):            >60dB

Port to Port Isolation (Rx Band):            >65dB

Antenna to Port Isolation (Tx Band):    >60dB

Intermod products:                            < -36dBm in transmit band
< -110dBm in receive band

LNA noise figure:          3dB at 2dB gain

VSWR:                             1.5:1

Connectors:                   BNC

Power Supply:              12V @ 15A (Model A)
12V @ 1A (Model B)

Dimensions:                  6u 19” rack (266mm x 483mm x 470mm)

Click to download pdf datasheet