Abstract: An adaptive array antenna system for stable directivity control and waveform equalization even under poor multipath environment is provided. An output of antenna elements (A1011-A101n) is weight combined (A103), and is output through automatic frequency control (A106) and fractionally spaced adaptive transversal filter (A107) which have real number weights. Weight combination (A103) is initially carried out with weights for an eigen vector beam for the maximum eigen vector of the correlation matrix Rxx of a receive signal After carrier synchronization and timing synchronization between a receive signal, and an A/D converter and a fractionally spaced transversal filter are established by the automatic frequency control and the fractionally spaced transversal filter, the weight in the weight combiner (A103) is switched to minimum mean square error (MMSE) weight.

Abstract: An adaptive array antenna transceiver apparatus provides: a local signal generator 24 that outputs a signal having a frequency that corresponds to the difference between the reception frequency and the transmitting frequency; a coupler 15 that separates and extracts a part of the signals from the output of the transmitters 13; a switch 21 that selects the signal output from any one of the transmitters 13; a frequency converter 22 that converts the frequency of the signal selected by the switch 21; and a switch 23 that inputs signals output by the frequency converter 22 and selectively outputs them to any one of the plurality of paths.

Abstract: A bidirectional printed antenna includes a dielectric substrate (33) having first and second surfaces which are substantially in parallel, at least one pair of radiation element conductors (31, 32) having the same shape and the same size, each pair of which is arranged on the first and second surfaces at positions opposing with each other, respectively, a feeding circuit (34, 35, 36, 37) coupled to at least one edge of each of the radiation element conductors, and a ground conductor (37) arranged on the second surface. The ground conductor (37) covers at least an area outside of the edge of the radiation element conductor, which edge is coupled to the feeding circuit, and an area outside of the opposite edge with respect to the radiation element conductor by leaving a gap of a predetermined width between the radiation element conductor and this ground conductor.

Abstract: A pair of bands are each secured at one end to one side of a case wherein a radio receiver is housed, and a monopole antenna having a length of 0.005.lambda. has one end connected to the feeding point of the radio receiver and its other end exposed to the outside of the case to form a contact portion for contact with the human body. A first helical antenna is supported to the one of the bands lengthwise thereof and is connected at one end to the feeding point. A second helical antenna is supported to the other band lengthwise thereof and is connected at one end to the common potential point of the radio receiver. The first and second helical antennas resonate, as one antenna, with the wavelength .lambda. used by the radio receiver, and their pitch P and helix area A are selected so that P<500A/.lambda. and P>150A/.lambda..