Transmit or receiver aerial covering VHF, UHF and SHF ranges - has long tube section with surface slot pattern and enclosed by metal plates

摘要

An antenna for use in the band of several 100 MHz has a tube (20) with a metallic inner surface and a cross-section that is either round or rectangular. The tube acts as a waveguide for electromagnetic waves and is from 3 to 33m long. Both ends of the tube are enclosed by metal plates (40) and a cable connection (10) is provided. Radio wave emissions are received and transmitted through slots formed (30) in the side walls of the section. ADVANTAGE - Acurrate directional characteristic.