Inspec keywords: strip lines; baluns; UHF antennas; varactors; antenna accessories; antenna feeds; band-pass filters

Other keywords: prototype balun; operating bandwidth; frequency-independent phase difference; novel bandwidth-tunable filtering balun; frequency 1.53 GHz; filtering property; vertical double-sided parallel-strip line; shunt varactor diodes; transmission-line circuits; noise figure 10.0 dB; compact 3D configuration; flexible bandwidth tunability; ring resonator; two-layer horizontal; complete horizontal ground; inserted vertical ground; frequency 0.87 GHz to 1.23 GHz

Subjects: Waveguide and microwave transmission line components; Single antennas; Passive filters and other passive networks; Waveguides and microwave transmission lines; Antenna accessories; Junction and barrier diodes