I.Y. Kolchugin

This article is about perspectives of building and using transmitting active multiple-beam HF-band circular antenna arrays. Exchange between traditional highly-effective HF-band antennas unable to perform azimuth scanning and multiple-beam antenna arrays is important way to improve competitivity of HF-band radio. Circular antenna arrays best serve every azimuth direction. Modernization of existing receive HF-band radiocenters already started with branch of NIIR - SONIIR taking active part in it. The question is can we use same principles in transmitting antennas to perform similar modernization of transmitting HF-band radiocenters. Research performed in branch of NIIR - SONIIR resulted in main principles of building multiple-beam circular antenna arrays using LC-network as beam-forming ones (receive variant). Main equations to synthesize LC-network are given. Array emitter construction as vertical vibrator combined with amplifier (active vibrator) is explained. Example of one particular device is given. Transmitting multiple-beam arrays are also mentioned in branch of NIIR - SONIIR research. It is suggested to use active vibrators, which will allow beamforming on low signal levels and active use of receive LC-networks. Main problem is interface between vibrator and amplifier. Results of research proving this problem is not an unsolvable one are briefly mentioned. Main problems that are to be solved to open perspectives of creating transmitting active multiple-beam circular antenna arrays using LC-networks as beamforming ones are named.