Generation of the current normal to the surface of antenna by electromagnetic waves and its application in the high responsive receiver

Generation of the initial current normal to the surface of antenna by electromagnetic waves has been considered. It has been shown that the angle of grazing (or sliding) for the wave with the electric vector in the plane normal to the surface varies the radiation resistance over a wide range. This property allows matching the radiation impedances and loads. Here, it has been proposed to use this property to create a highly- sensitive radiation detector. In relation with this task, a model of the radiation detection of the input radiation signal by a direct quadratic detector in the stationary mode with the diode included as the load has been considered. The obtained results prove that a diode with the high differential resistance can effectively operate with the antenna. The rise of the resistance increases the detector response voltage, its responsivity, and decreases the receiver noise equivalent power. Improvement of these characteristics by orders of magnitude is possible. The considered mechanism allows detectors to operate in the infrared spectral range, and the increase in the wavelength, in principle, does not limit its functioning.

UHF HIGH-Tc SQUID

For the first time we have designed, constructed and investigated an UHF high-T c SQUID pumped at 360 MHz at 77 K. The SQUID is based on an one-hole interferometer with a microbridge Josephson contact made of bulk YBaCuO ceramics by the standard technique of mechanical scribing, followed by finishing with a high-voltage discharge electroerrosion. Magnetic flux sensitivity of the UHF SQUID as measured by the output signal of a quadratic detector with a dc amplifier of 40 kHz bandwidth was found to be about 5 × 10−5ϕ0/ Hz 1/2 in the quasiwhite noise region (at a frequency over 700 Hz).