This tunable antenna provides exceptional gain in the 30-88 MHz SINCGARS band compared to similarly sized passive antennas whilst maintaining optimum performance right up to 512 MHz. Many years of experience in designing solid-state tuned antennas has enabled CAL’s team to provide the ultimate in performance and reliability for a frequency agile airborne blade. Close attention to environmental, EMI and harmonic generation design considerations combined with latest composites structural technology makes the 21-150-02 suitable for helicopters and subsonic aircraft, particularly when there is low ground clearance. The separate logic converter unit combines flash memory technology with MIL spec’d power supply in a MIL-STD-461 compliant package. LCU’s can be programmed for all modern digital transceivers. A unique feature of this antenna design is that the main radiating element is passive, symmetrical and matched for the UHF band and the p-i-n diode tuning circuitry only operates in VHF and is enclosed within the radiating element. In this way, excellent azimuthal omni-directivity is maintained throughout the entire frequency band. Excellent VHF low band gain is additionally achieved by the thin section top loading plate.