Apparatus and method for implementing a low-noise amplifier and mixer

An apparatus for generating an intermediate signal, comprising:

• a mixer, the mixer configured to receive a first signal having a first frequency and a second signal having a second frequency, and to output a third signal which is a function of the first and second signals;
• a circuit module, the circuit module comprising a first circuit stage and a second circuit stage and configured to modify an electrical signal which is input into the mixer as the first signal, the first and second circuits being in communication via a first signal path and a second signal path;
• and
• an interface circuit, the interface circuit interposed between the mixer and the circuit module, and inserted into the second signal path so that a bias current flows between the first circuit and the second circuit via the interface module.

A method for generating an intermediate signal, comprising the steps of:

• providing an apparatus comprising a mixer, a circuit module which comprises a first circuit and a second circuit and an interface circuit, the interface circuit interposed between the mixer and the circuit module;
• operating the first and second circuits so that a current flows between the first and second circuits via the interface circuit;
• modifying a first signal with the first circuit and feeding the modified first signal to the second circuit;
• modifying the modified first signal with the second circuit to generate a second signal;
• generating a third signal, the third signal being dependent from the second signal;
• and
• mixing the third signal and a fourth signal with the mixer to generate the intermediate signal.

A method for amplifying an electrical signal, comprising the steps of:

• providing an apparatus comprising a circuit module which comprises a first circuit and a second circuit and an interface circuit, the interface circuit associated with the circuit module and an output of the apparatus, wherein the first and second circuits being in communication via the first signal path and a second signal path;
• modifying a first signal with first circuit and feeding the modified first signal to the second circuit via the first signal path;
• operating the first and second circuits so that a current flows between the first and second circuits via the second signal path within the interface circuit;
• modifying the modified first signal with the second circuit to generate a second signal;
• and
• generating a third signal, the third signal being dependent from the second signal.

A method for amplifying an electrical signal, comprising the steps of:

• interconnecting a first amplifier stage, an interface circuit, and a second amplifier stage, wherein the first amplifier stage and the second amplifier stage being in communication via a first signal path and a second signal paths;
• conveying a first radio signal between the first amplifier stage and the second amplifier stage on the first signal path;
• conveying a bias current through the interface circuit;
• and
• conveying a second radio signal through the interface circuit.

A method for amplifying an electrical signal, comprising the steps of:

• interconnecting a first amplifier stage, an interface circuit, and a second amplifier stage;
• conveying a bias current through the interface circuit by conveying a direct current through a primary winding of transformer;
• and
• conveying a radio signal through the interface circuit.