Abstract: There is described a receiver of at least one radiofrequency modulated signal deriving from an antenna external to the receiver; the receiver comprises a first stage for the low noise amplification of the radiofrequency modulated signal and a demodulation stage of the above-mentioned signal. The receiver comprises a SAW filter adapted to act as a pass band filter about a predetermined frequency for the signal deriving from the first stage, a logarithmic amplifier adapted to amplify the signal deriving from the SAW filter, a peak detector of the output signal of the logarithmic amplifier, means adapted to control the gain of the first stage for the amplification of the radiofrequency modulated signal as a function of the output signal (Vopeak) of the peak detector.

Abstract: There is described a receiver of at least one radiofrequency modulated signal deriving from an antenna external to the receiver; the receiver comprises a first stage for the low noise amplification of the radiofrequency modulated signal and a demodulation stage of the above-mentioned signal. The receiver comprises a SAW filter adapted to act as a pass band filter about a predetermined frequency for the signal deriving from the first stage, a logarithmic amplifier adapted to amplify the signal deriving from the SAW filter, a peak detector of the output signal of the logarithmic amplifier, means adapted to control the gain of the first stage for the amplification of the radiofrequency modulated signal as a function of the output signal (Vopeak) of the peak detector.

Abstract: A compacted patch antenna is described, particularly for installation in a vehicle, comprising an electrically supplied strip radiating element and a ground plane. The strip radiating element is connected to the ground plane at a first end by means of a metal link and at a second end, opposite to the first end, by means of a variable capacitor. The compacted patch antenna comprises a printed circuit, the bottom surface of which is integral with the ground plane, a dielectric material layer arranged between the strip radiating element and the printed circuit; the strip radiating element is substantially parallel to the ground mass. The dielectric material layer has a relative dielectric constant ranging between 3 to 6 with a loss factor ranging between 0.03 to 0.1.

Abstract: A driving circuit of a surface wave resonator (X1) is described; the resonator comprises a static capacitor (Co) and the driving circuit is adapted to supply a voltage (Vx) to the resonator. The driving circuit comprises reactive means (L3) adapted to resonate in combination with said static capacitor (Co) of the resonator at a predetermined frequency (Fo) in the initial driving period of the resonator at said voltage; the driving circuit comprises passive means (R3) adapted to determine oscillations at said predetermined frequency (Fo).

Abstract: A driving circuit of a surface wave resonator (X1) is described; the resonator comprises a static capacitor (Co) and the driving circuit is adapted to supply a voltage (Vx) to the resonator. The driving circuit comprises reactive means (L3) adapted to resonate in combination with said static capacitor (Co) of the resonator at a predetermined frequency (Fo) in the initial driving period of the resonator at said voltage; the driving circuit comprises passive means (R3) adapted to determine oscillations at said predetermined frequency (Fo).