The AE1.5H9786 from Anatech Electronics is a high pass filter with a cutoff frequency of 1.5 MHz. The filter has an insertion loss of less than 0.5 dB, return loss over 15 dB with rejection of more than 51 dB at 568 KHz. The AE200H9897 can handle a power of up to 10 dBm. It is available in a module that measures 2.5 x 1.125 x 0.75 inches with BNC male/female connectors.
