Bird - The RF Experts
Duplexers

Bird manufacturers a comprehensive line of duplexers with the critical specifications you require to operate a high performance system. Whether your application has a challenging T-R frequency spacing or requires broadband duplexed windows to implement a single antenna system, our duplexers provide the transmitter and noise suppression characteristics you need while minimizing the loss to your carriers.

A Duplexer (or diplexer as they are sometimes called) is a 3-port device most commonly used to allow a transmitter and receiver, operating on different frequencies, to share a common antenna while operating simultaneously. The filters that make up the duplexer isolate the transmitter from the receiver by doing two important functions - the most important is filtering out any transmitter noise sidebands that are being generated on the receive frequency. The second function is protecting the receiver from transmitter carrier overload. The amount of isolation necessary is dependent upon the TX to RX frequency spacing. As the frequencies get closer, a higher value of isolation is required.

At high-band VHF and UHF, the Vari-Notch® design is the most commonly used. Vari-Notch® provides a low-loss pseudo-bandpass characteristic that can exist very close to a deep notch. Proven low-loss and low-noise construction techniques are used such as welded cavity construction; silver-plated loops, Alballoy®-plated integrated loop plates and connectors; as well as a unique fingerstock-free high-conductivity silver-plated tuning probe. Our 4” and 6.625” diameter cavities are constructed of hardened aluminum which, unlike most copper cavities, resists denting and associated detuning.

At 700/800/900 MHz where there are large guard bands and multiple frequencies per system, the Bandpass duplexer fills the bill nicely. The combline filter design is both low-loss and space-efficient. For duplexing a single repeater, the Vari-Notch® design is still the product of choice. Vari-Notch® provides a low-loss pseudo-bandpass characteristic that can exist very close to a deep notch. Proven low-loss and low-noise construction techniques are used such as welded cavity construction; silver-plated loops, Alballoy®-plated integrated loop plates and connectors; as well as a unique fingerstock-free high-conductivity silver-plated tuning probe. Our cavities are constructed of hardened aluminum which, unlike most copper cavities, resists denting and associated detuning.

0-135 MHz
RF Duplexers
136-174 MHz
RF Duplexers
175-379 MHz
RF Duplexers
380-530 MHz
RF Duplexers
531-895 MHz
RF Duplexers
896-3000 MHz
RF Duplexers