Receiver for an integrated heterodyne communication system including BAW-type resonators

A hetero dyne receiving circuit for a digital communication system, comprising:

• a band pass first filter receiving a signal generated by an antenna, said first filter including a first BAW-type tunable resonator component which is adjustable by a first electrical signal;
• a narrow band pass second filter which is located downstream with respect to said first filter;
• said second filter including a second BAW-type tunable resonator component which is adjustable by a second electrical signal different than the first electrical signal;
• and
• a mixer for mixing a signal outputted by said second filter with a local oscillation frequency in order to generate an intermediate frequency.

A digital communication system, comprising:

• an antenna that receives a communication signal and generates a corresponding signal;
• and
• a heterodyne receiving circuit coupled to the antenna and including:
• a band pass first filter receiving the corresponding signal generated by the antenna, said first filter including a first BAW-type tunable resonator component which is adjustable by a first electrical signal, said first electrical signal being generated by a first PLL-type frequency control loop;
• an amplifier located downstream with respect to said first band pass filter;
• a narrow band pass second filter which is located downstream with respect to said amplifier and said first filter, said second filter receiving a band of frequencies which is filtered by said first filter;
• said second filter including a second BAW-type tunable resonator component which is adjustable by a second electrical signal, said second electrical signal being generated by a second PLL-type frequency control loop which has a variable division factor for selecting one particular channel within said band of frequencies;
• a mixer for mixing a signal outputted by said second filter with a local oscillation frequency in order to generate an intermediate frequency;
• and
• a digital processing system for processing said intermediate frequency;
• wherein said first filter is based on a master/slave circuit which further includes:
• a slave circuit that generates a transfer function of said first filter, said slave circuit having a first BAW resonator having a resonant frequency and an anti-resonant frequency, said first BAW resonator being associated with an inductive first partner element having a resonant frequency fixed in the vicinity of said resonant and anti-resonant frequencies of the first BAW resonator;
• and with a capacitive second partner element, at least one of the two partner elements being adjustable by said first electric signal;
• and
• a master circuit having a second BAW resonator located on a same substrate as said first BAW resonator, and having a resonant frequency and an anti-resonant frequency, said second BAW resonator being associated with an inductive third partner element having a resonant frequency fixed in the vicinity of said resonant and anti-resonant frequencies of the second BAW resonator;
• and with a capacitive fourth partner element, at least one of the two partner elements of the master circuit being adjustable by said first electric signal;
• said second BAW resonator being integrated within said first PLL frequency control loop so as to generate said first electrical signal.

A hetero dyne receiving circuit for a digital communication system, comprising:

• first filter means receiving a signal generated by an antenna, said first filter means including first BAW-type tunable resonator means which are adjustable by a first electrical signal, said first electrical signal being generated by first frequency control means;
• amplifier means located downstream with respect to said first filter means;
• second filter means located downstream with respect to said amplifier means and said first filter means, said second filter means receiving a band of frequencies which is filtered by said first filter means;
• said second filter means including second BAW-type tunable resonator means which are adjustable by a second electrical signal different than the first electrical signal, said second electrical signal being generated by second frequency control means which have a variable division factor for selecting one particular channel within said band of frequencies;
• mixer means for mixing a signal outputted by said second filter means with a local oscillation frequency in order to generate an intermediate frequency;
• and
• digital processing means for processing said intermediate frequency.