We build various types of combiners composed of cavity filters to use multiple transmitters installed in a single transmission site with a single antenna system.
• A star-point diplexer is made by parallel circuiting two band pass filters having
different pass bands. Care must be taken, however, to ensure that the impedance
transformed by the one band pass filter at the junction point does not affect the
pass band of the other filter
The double balanced bridge consist of units, each comprising two band pass filters,
two 3 dB couplers an and a dummy resistors (absorber).
• One of both inputs has a narrow band characteristic, while the remaining input
features a broadband characteristic.
• Frequency independent input impedance
• The frequency at the broadband input can be varied without retuning of the passband cavity filters.
• The broadband input can be used as spare input for expansion without requiring
modification of the existing pass-band cavity filters.
• If only narrow band input is being used, an extremely high coupling attenuation
(directional coupler attenuation plus filter attenuation) can be achieved for very
small frequency spacings.
