Search

EP-4624995-B1 - TERAHERTZ SENSORS AND RELATED SYSTEMS AND METHODS

EP4624995B1EP 4624995 B1EP4624995 B1EP 4624995B1EP-4624995-B1

Inventors

  • CHARVAT, GREGORY L.
  • SAIZ, Nicholas
  • CAREY, MATTHEW

Dates

Publication Date
20260513
Application Date
20220621

Claims (15)

  1. A device, comprising: a substrate (10); a first semiconductor die (12), mounted on the substrate, having a radio-frequency, RF, transmit antenna array (102) integrated thereon; a second semiconductor die (14), mounted on the substrate, having an RF receive antenna array (104) integrated thereon; signal generation circuitry (16) at least partially mounted on the substrate, the signal generation circuitry coupled to the first semiconductor die and to the second semiconductor die; a power divider (111) which couples the signal generation circuitry to the first semiconductor die, wherein the power divider is defined by conductive traces patterned on the substrate; and processing circuitry (18) coupled to the RF receive antenna array and configured to determine a distance between the device and a target object using a signal received by the RF receive antenna array.
  2. The device of claim 1, wherein the signal generation circuitry (16) comprises: an oscillator (160) configured to generate a first signal; a signal generator (162) configured to generate a second signal having a time-varying center frequency by frequency modulating the first signal; and frequency-up conversion circuitry (164) configured to generate a third signal by up-converting the second signal.
  3. The device of claim 2, wherein the first signal has a center frequency in a range of 1 GHz - 20 GHz, and wherein the frequency up-conversion circuitry (164) is configured to up-convert the second signal by a factor between 30 and 80.
  4. The device of claim 2, wherein the frequency up-conversion circuitry (164) comprises a plurality of frequency multipliers (122), and wherein the power divider (111) is configured to provide the second signal to at least some of the plurality of frequency multipliers.
  5. The device of claim 4, wherein the frequency multipliers (122) are coupled to respective antennas of the transmit RF antenna array (102), and wherein the power divider (111) is configured to cause the antennas of the RF transmit antenna array to transmit RF signals in phase with respect to one another.
  6. The device of claim 2, wherein the frequency multipliers (122) are coupled to respective antennas of the transmit RF antenna array (102), and wherein the signal generation circuitry (16) further comprises a plurality of phase shifters (128) configured to cause the antennas of the RF transmit antenna array (102) to transmit RF signals in phase with respect to one another.
  7. The device of claim 4, wherein the plurality of frequency multipliers (122) comprises a plurality of harmonic frequency multipliers, each comprising a non-linear circuit configured to generate one or more harmonics of an input frequency of the second signal generated by the signal generator.
  8. The device of claim 2, wherein antennas of the RF transmit antenna array (102) and antennas of the RF receive antenna array (104) are arranged to receive the third signal generated by the frequency up-conversion circuitry (164).
  9. The device of any preceding claim, wherein the second semiconductor die (14) comprises receive circuitry configured to frequency down-convert the signal received by the RF receive antenna array (104).
  10. The device of claim 1, wherein the first semiconductor die (12) comprises a first semiconductor type and the second semiconductor die (14) comprises a second semiconductor type different from the first semiconductor type.
  11. The device of claim 1, wherein the RF transmit antenna array (102) is configured to transmit an RF signal having power level in a range of 10 dBm - 30 dBm.
  12. The device of claim 11, wherein the processing circuitry has a noise figure (NF) between 10 dB and 40 dB.
  13. The device of claim 11, wherein the RF transmit antenna array (102) has an aperture between 1 cm 2 and 5 cm 2 and an angular resolution between 0.4° and 1° in the frequency band 300 GHz - 3 THz.
  14. The device of claim 1, wherein the second semiconductor die (14) further comprises a plurality of sub-harmonic mixers (310) and a plurality of analog-to-digital converters, ADCs, coupled to the plurality of antennas of the RF receive antenna array (104), wherein the plurality of sub-harmonic mixers are coupled to the plurality of ADCs and the plurality of antennas of the RF receive antenna array, wherein the sub-harmonic mixers are configured to generate output signals by mixing signals received from the RF receive antenna array with reference signals generated by the signal generation circuitry (16) and provide the output signals to the plurality of ADCs.
  15. A method for controlling the device of any preceding claim to determine the distance between the device and the target object, the method comprising: controlling the signal generation circuitry (16), the power divider (111) and RF transmit antenna array (102) to transmit a signal; controlling the RF receive antenna array (104) to receive a signal resulting from a reflection of the transmitted signal from the target objection; and controlling the processing circuitry (18) to determine the distance between the device and the target object based on the received signal.

Description

BACKGROUND Autonomous vehicles, such as self-driving cars, are vehicles equipped with sensors capable of sensing the surrounding environment, which helps the vehicles move without human intervention. Autonomous vehicles have been under development for decades. It is estimated that vehicles that are autonomous to at least some degree will represent more than half of all vehicles produced by 2024. In recent years, billions have been invested in the pursuit of fully autonomous vehicles. Notwithstanding, the development and deployment of fully autonomous vehicles require significant advances in technology. WO 2021/079361 discloses a method for production of a phased array, wherein the individual antenna elements are produced as part of silicon semiconductor devices, or are fabricated upon the packages of such devices. Antenna-on-package devices are available as off-the-shelf devices, and WO 2021/079361 A1 introduces a method for the use thereof in a phased array antenna implemented on PCB. All signals are transmitted in digital form from a control processor to the transmit antenna arrays and from the receive antenna arrays to the processor, saving transmission losses and propagation delays. "A 120-GHz Wideband FMCW Radar Demonstrator Based on a Fully-Integrated SiGe Transceiver with Antenna-in-Package" by Muhammad Furqan et al in 2016 IEEE MTT-S INTERNATIONAL CONFERENCE ON MICROWAVES FOR INTELLIGENT MOBILITY (ICMIM), IEEE, 19 May 2016, pages 1-4, XP032938878, presents a fully-integrated D-Band bistatic frequency-modulated continuous-wave radar (FMCW) radar sensor based on a 130 nm SiGe BiCMOS technology for short-range applications. The radar sensor includes transmit and receive antennas integrated in an embedded-wafer-level-ball-grid-array (eWLB) package. The transceiver chip is based on x30 frequency multiplication, which enables the use of off-the-shelf 4 GHz phase-locked-loops. A fully-differential IQ receiver is implemented by means of a differential 3-dB branch line coupler. On-wafer measurements show a maximum output power of O dBm. The radar sensor is mounted on a low cost PCB and is used in conjunction with an FPGA based baseband board for analog-to-digital conversion, processing and evaluation of the IF signals. In order to verify the operation, FMCW measurements of static targets are performed with a sweep bandwidth of up to 10 GHz, which corresponds to a minimum range-resolution of 3 cm. The radar chip consumes around 560 mW from a 3.3V power supply and the package size is 12mm x 6mm. "Realization of Antenna Array at K Band with Tailored Azimuth and Elevation Beamwidths" by Sinisa P. Jovanovic et al in 2019 14TH INTERNATIONAL CONFERENCE ON ADVANCED TECHNOLOGIES, SYSTEMS AND SERVICES IN TELECOMMUNICATIONS (TELSIKS), IEEE, 23 October 2019, pages 148-151, XP033718503, describes the design, prototype realizations and measurement results of an antenna array developed for a short-range radar module, operating at unlicensed ISM range within the K frequency band. The radar module is suitable for sensing the presence of humans and other living beings inside a confined space by detecting their vital signs. The characteristics of the antenna array are specified in accordance with the projected working environment of the radar module as well as the characteristics of the Infineon transmitter, employed as a major active element. The antenna array is designed for achieving a specific beamwidth in the azimuth and elevation plane to ensure the coverage of the entire observed zone from a fixed position of the radar module. Two different types of feeding networks are designed, differential and single-ended, to match the corresponding inputs of the transmitter and to maximize the radiated power. SUMMARY There is provided a device as set out in claim 1. There is also provided a method for controlling the device, as set out in claim 15. BRIEF DESCRIPTION OF DRAWINGS Various aspects and embodiments will be described with reference to the following figures. It should be appreciated that the figures are not necessarily drawn to scale. FIG. 1A is a diagram illustrating the location of the Terahertz band along the electromagnetic spectrum.FIG. 1B is a schematic diagram illustrating an autonomous vehicle including different types of sensors.FIG. 2A is a plot illustrating radio-frequency (RF) attenuation as a function of rain rate at different frequencies.FIG. 2B is a table that relates the type and intensity of precipitation to the rain rate (R).FIG. 2C is a plot illustrating a solar spectral irradiance.FIG. 3A is a plot illustrating RF atmospheric attenuation as a function of the carrier frequency.FIG. 3B is a plot illustrating Terahertz sub-bands suitable to perform ranging, in accordance with some embodiments of the technology described herein.FIG. 4 is a table illustrating example system specifications, in accordance with some embodiments of the technology described herein.FIG. 5A illustrates a system for Terahertz-based