FDP2 Filter Antenna
FDP2 Filter Antenna


The FDP2 is an RF filter that is used in receiver and transmitter applications. The filter is factory tuned to a frequency between 512MHz and 692MHz.

For Transmitters

When connected to a transmitter, the filter eliminates transmitter RF noise outside the 35MHz window generated by the transmitter. The filter pushes the noise level down by an additional 50 dB allowing the transmitter antenna to be located very close to receiving antennas without the receiver desensitization that can happen without the filter.


For receivers

In a receiver application, the filter eliminates unwanted RF outside the bandpass of the filter that might interfere with the reception of intended wireless microphones. For example, a walkie-talkie on 460MHz might interfere with a wireless receiver operating at 520 MHz. The use of the filter should knock down the walkie signal so that it does not overload the wireless receiver.

Frequency Choices

FDP2 can be ordered on any frequency within the frequency range of 512-592 MHz. The frequency ordered is the center of the filter meaning that signals 17.5 MHz above and below the center can pass through the filter. The FDP2 is compatible with any RF transmitter or receiver from any manufacturer to eliminate interference.

Frequency block choices are as follows:

Block 20: 518-542 MHz
Block 21: 536-572 MHz
Block 22: 560-590 MHz
Block 23: 590-614 MHz
Block 24 – 614-644 MHz
Block 25 – 638-668 MHz
Block 26 – 662-692 MHz
(Blocks 24 – 26 are no longer available for sale or use in the USA)

The filters operational bandwidth is 35 MHz. The filter rolls off at about 2dB per MHz outside the filter’s bandpass. The farther away the interference is from the filters center the better it will work.