A new compact design of diplexer with high electrical performances is proposed for base station antennas operating within frequency bands 2.3–2.4/2.49–2.69 GHz. The diplexer consists of two interdigital band-pass filters and coaxial power divider. Proposed design has high potential from view poin of implementation of wide-band as well as medium and narrow bands filters. The fabricated diplexer shows the following measured characteristics: reflection coefficient is -18 dB within passbands, insertion loss is -0.28 dB, isolation of ports is -30 dB. Diplexer has the relatively simple easy to manufacture design and compact dimensions, so it may be directly integrated into the base station antennas
