BPBR 4/4 / BRBP 4/4
Band-Pass/Band-Reject Filters for the 80 MHz Band
Description
- The BPBR 4/4 and the BRBP 4/4 are 4-cavity pass-reject filters, which pass one frequency or frequency band and reject another in immediate vicinity of the pass frequency.
- The filters are delivered in two basic models: The BPBR-types have the reject range on the high side of the pass frequency and the BRBP-types have the reject range situated on the low side of the pass frequency.
- These filter types can be used to protect a receiver against interference from a nearby transmitter. The filters are tuned to reject the interfering signal. Pass-reject-type filters are applied when the spacing between the utility signal and the interfering signal is so small, that the slope steepness of normal band-pass filters or notch filters are not sufficient to provide adequate rejection.
- The filters are primarily intended to pass and reject two single frequencies, but the filters can also be tuned to pass and reject several single frequencies or to having a certain pass and reject port bandwidth. In these cases factory-tuning is recommended.
- The standard BPBR-filters can be tuned within the complete 4 m-band with 2 to 16 MHz spacing between the operating frequencies.
- Insertion loss is below 1.3 dB at spacings between 3 and 16 MHz. At the narrowest spacing of 2 MHz, insertion loss is kept under 2.0 dB.
- The filters have very small dimensions ove to the use of high-Q helical resonators with discrete-component interconnections.
- The housing is made of extruded aluminium, the chassis of passivated steel, and the connectors are provided with teflon insulation.
- The filters are black vinyl coated to prevent corrosion.
- Careful design and choice of materials ensure reliable operation over a wide temperature range.