Quasi-optical transceiver having an antenna with time varying voltage

A method of transmitting and receiving radiation, the method comprising:

• a) providing a first light source that generates a first beam of light at a first frequency;
• b) providing a second light source that generates a second beam of light at a second frequency;
• c) modulating a conductance of a first photomixer at a difference frequency approximately equal to the difference between the first and the second frequencies in response to the first and the second light beam to generate a signal having the difference frequency;
• d) transmitting the signal;
• e) receiving the signal transmitted;
• f) generating a time varying voltage in response to the signal received;
• g) modulating a conductance of a second photomixer at the difference frequency in response to the first and the second light beam;
• and
• h) generating a current signal in response to the time varying signal received by the second antenna and the modulated conductance of the second photomixer.

A method of performing real time spectroscopy comprising:

• a) providing a first light source that generates a first beam of light at a first frequency;
• b) providing a second light source that generates a second beam of light at a second frequency;
• c) modulating a conductance of a first photomixer at a difference frequency approximately equal to the difference between the first and the second frequencies in response to the first and the second light beam to generate a signal having the difference frequency;
• d) transmitting the signal through a medium to be analyzed;
• e) receiving the signal;
• f) generating a time varying voltage in response to the signal;
• g) modulating a conductance of a second photomixer at the difference frequency in response to the first and the second light beam;
• h) generating a current signal in response to the time varying signal received by the second antenna and the modulated conductance of the second photomixer;
• i) measuring at least one of amplitude or phase of the current signal;
• and
• j) determining at least one of absorption or dispersion characteristics of the medium from the amplitude or phase measurement.

A method of imaging, an object, the method comprising:

• a) providing a first light source that generates a first beam of light at a first frequency;
• b) providing a second light source that generates a second beam of light at a second frequency;
• c) modulating a conductance of a first photomixer at a difference frequency approximately equal to the difference between the first and the second frequencies in response to the first and the second light beam to generate a signal having the difference frequency;
• d) transmitting the signal through an object to be imaged;
• e) receiving the signal transmitted;
• f) generating a time varying voltage in response to the signal;
• g) modulating a conductance of a second photomixer at the difference frequency in response to the first and the second light beam;
• h) generating a current signal in response to the time varying signal received by the second antenna and the modulated conductance of the second photomixer;
• i) measuring at least one of amplitude or phase of the current signal;
• and
• j) processing at least one of the amplitude or phase of the current signal to form an image of the object.

A method of network analysis comprising:

• a) providing a first light source that generates a first beam of light at a first frequency;
• b) providing a second light source that generates a second beam of light at a second frequency;
• c) modulating a conductance of a first photomixer at a difference frequency approximately equal to the difference between the first and the second frequencies in response to the first and the second light beam to generate a signal having the difference frequency;
• d) transmitting the signal to a network to be analyzed;
• e) receiving the signal;
• f) generating a time varying voltage in response to the signal;
• g) modulating a conductance of a second photomixer at the difference frequency in response to the first and the second light beam;
• h) generating a current signal in response to the modulated conductance of the second photomixer;
• i) measuring at least one of amplitude or phase of the current signal;
• and
• j) processing at least one of the amplitude or phase of the current signal to determine at least one of a transmission or a reflection parameter of the network.