Adaptive receivers

An adaptive receiver for receiving a radio frequency (RF) signal and converting the RF signal at a frequency FRF toward an intermediate frequency (IF) signal at a frequency FIF,AD, the adaptive receiver comprising:

• a pair of band pass filters, each with a nominal center frequency at FIF,
• a one-dimensional look-up table configured to provide an intermediate frequency offset Δf as a function of the difference between two tone voltages, ΔVFX2-FX1;
• wherein the voltage difference ΔVFX2-FX1 (=VFX2−VFX1) is determined based on measured voltages VFX2 and VFX1 for two frequencies;
• a micro controller configured to, using the ΔVFX2-FX1 value, determine the frequency offset Δf from the one-dimensional look-up table and compute an adaptive intermediate frequency FIF,AD equal to the sum of the nominal intermediate frequency FIF and Δf;
• and
• a local oscillator to generate sinusoidal signals at a frequency FLO equal to FRF minus FIF,AD.

An adaptive receiver for receiving a radio frequency (RF) signal and converting the RF signal at a frequency F toward an intermediate frequency (IF) signal at a frequency FIF,AD, the adaptive receiver comprising:

• a band pass filter with a nominal center frequency at FIF,
• a one-dimensional look-up table configured to provide an intermediate frequency offset Δf as a function of the difference of two tone voltages, ΔVFX2-FX1;
• wherein the voltage difference ΔVFX2-FX1 (=VFX2−VFX1) is determined after the adaptive receiver is powered on at temperature Ton, based on measured voltages VFX2 and VFX1 for two frequencies;
• a temperature sensing device to detect the temperature difference ΔT (=Ton−Top) between an operating temperature Top and the temperature Ton;
• a micro controller configured to, using the ΔVFX2-FX1 value, determine the frequency offset Δf from the one-dimensional look-up table and compute an adaptive intermediate frequency FIF,AD equal to the sum of the nominal intermediate frequency FIF, Δf and Fslope×ΔT, where Fslope is the FIF+Δf slope coefficient related to temperature difference ΔT;
• and
• a local oscillator to generate sinusoidal signals at a frequency FLO equal to FRF minus FIF,AD.