Transmit and receive techniques for terahertz sensing systems

A method for use with a device, the device comprising a substrate having a transmitter mounted thereon, the substrate defining a plane extending in a first direction and a second direction that are substantially orthogonal to one another, the transmitter comprising a first transmit semiconductor die having integrated thereon a first plurality of transmit RF antennas and first transmit circuitry, the first transmit circuitry comprising a first frequency multiplier comprising an input, an output, and a transistor circuit, and the transistor circuit comprising a control terminal, a first channel terminal, and a second channel terminal, the method comprising:

• generating, using the first transmit circuitry, first RF signals having a first RF center frequency in a particular frequency range within a range of 300 GHz to 1.5 THz at least in part by:
• obtaining, using the control terminal of the transistor circuit, a reference RF signal at the input of the first frequency multiplier;
• generating, using the first channel terminal of the transistor circuit, a first RF signal of the first RF signals having the first RF center frequency at the output of the first frequency multiplier;
• and
• controlling, using the control terminal and the first channel terminal, coupling between the first channel terminal and the second channel terminal;
• and
• transmitting, using the first plurality of transmit RF antennas, the first RF signals.

A device, comprising:

• a substrate defining a plane extending in a first direction and a second direction that are substantially orthogonal to one another;
• signal generation circuitry mounted on the substrate and configured to generate a reference RF signal;
• a transmitter mounted on the substrate, the transmitter comprising:
• a first transmit semiconductor die having integrated thereon:
• first transmit circuitry configured to generate first RF signals having a first RF center frequency in a particular frequency range within a range of 300 GHz to 1.5 THz, the first transmit circuitry comprising:
• a first frequency multiplier comprising an input, an output, and a transistor circuit comprising:
• a control terminal configured to obtain a second reference RF signal, generated based on the reference RF signal, at the input;
• a first channel terminal configured to generate a first RF signal of the first RF signals at the output having the first RF center frequency;
• and
• a second channel terminal, wherein the control terminal and the first channel terminal are configured to control coupling between the first channel terminal and the second channel terminal;
• and
• a first transmit antenna array comprising a first plurality of transmit RF antennas configured to transmit the first RF signals;
• a receiver mounted on the substrate, the receiver comprising:
• a first receive semiconductor die having integrated thereon:
• a first receive antenna array comprising a first plurality of receive RF antennas configured to receive second RF signals having the first RF center frequency;
• and
• first receive circuitry configured to mix the second RF signals with third RF signals, generated based on the reference RF signal, to obtain fourth RF signals;
• interface circuitry mounted on the substrate and coupled to the first receive circuitry, the interface circuitry comprising analog-to-digital conversion (ADC) circuitry configured to digitize the fourth RF signals to obtain digitized fourth RF signals;
• and
• processing circuitry mounted on the substrate and coupled to the interface circuitry, the processing circuitry configured to determine, based on the digitized fourth RF signals, a distance between the device and a target object that reflected the first RF signals to generate, at least in part, the second RF signals.