Super-regenerative circuit apparatus for a door operator receiver and door operator incorporating the same

A super-regenerative receiver for a radio frequency (RF) controlled electrical garage door, said receiver comprising:

• a super-regenerative circuit including a tuned circuit tuned to an operational frequency and a quench oscillator that periodically enables and inhibits said super-regenerative circuit according to a quench frequency, said super-regenerative receiver producing an output signal with said operational frequency and said quench frequency superimposed;
• a cascode circuit connected to an input of said super-regenerative circuit as a preamplifier stage therefor, said cascode circuit including a field effect transistor (FET) and a bipolar transistor connecting said FET to said super-regenerative circuit, said FET and said bipolar transistor cooperating to produce very low gain in a direction from said input of said super-regenerative circuit to an input of said cascode circuit to thereby decrease RF radiation emitted from said super-regenerative circuit;
• and
• a band pass filter connected to an input of said cascode circuit.

A radio frequency (RF) controlled door operator responsive to RF signals from an associated remote RF transmitter, said door operator comprising:

• a motor for opening and closing a door;
• a super-regenerative receiver for recovering a data signal from a received RF signal, said receiver including
• a super-regenerative circuit with an input and an output;
• a cascode preamplifier stage connected to said input of said super-regenerative circuit for amplifying a received RF signal to provide an amplified signal and applying its amplified signal to said super-regenerative circuit, said preamplifier stage including a field effect transistor (FET) and a bipolar transistor connecting said FET to said super-regenerative circuit, said FET and said bipolar transistor cooperating to produce low gain in a direction from said input of said super-regenerative circuit to an input of said preamplifier stage,
• data amplifier means having an input connected to said output of said super-regenerative circuit for recovering a data signal from an output signal from said super-regenerative receiver circuit, and
• decoder means connected to said data amplifier means for decoding a data signal applied thereto by said data amplifier means and generating a decoded control signal therefrom;
• and
• control means, responsive to a decoded control signal from said decoder means, for controlling said motor.

A preamplifier stage for a super-regenerative circuit in a radio frequency (RF) receiver for use in an electrical door opener, said preamplifier stage comprising:

• an input for receiving an RF signal;
• an output adapted to connect said preamplifier stage to a super-regenerative circuit;
• and
• a cascode circuit connected to said input, said cascode circuit including a field effect transistor (FET) and a bipolar transistor connecting said FET to said output, said FET and said bipolar transistor cooperating to produce low gain in a direction from said output to said input to thereby decrease RF radiation emitted from a super-regenerative circuit connected to said output.

A method of signal amplification in a super-regenerative receiver for use in an electrical door opener, said method comprising the steps of:

• providing a super-regenerative circuit with an input and an output;
• providing a cascode preamplifier stage upstream of said super-regenerative circuit, said cascode preamplifier stage including an input for receiving a RF signal, an output for coupling said preamplifier stage to said input of said super-regenerative circuit, a field effect transistor (FET), and a bipolar transistor connecting said FET to said output of said cascode preamplifier stage;
• resistively loading said FET and said bipolar transistor to increase stability in said preamplifier stage;
• phase shifting a RF signal applied to said input of said preamplifier stage;
• and
• providing low impedance coupling means between said input of said super-regenerative circuit and said output of said preamplifier stage.