Antenna-sub harmonic mixer block and terahertz image scanner including the same

Patent metadata

Field	Value
Publication number	US-12489228-B2
Application number	US-202318325631-A
Country	US
Kind code	B2
Filing date	May 30, 2023
Priority date	Aug 18, 2022
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Disclosed is an antenna-sub harmonic mixer block, which includes a dielectric block disposed on a PCB substrate having a ground surface, an antenna including first antenna patch provided on the dielectric block and having a metal patch and a slot, and a second antenna patch provided on the dielectric block, spaced apart from the first antenna patch to surround the first antenna patch, and that receives a ground voltage at the same potential as the ground surface of the PCB substrate, an RF ground wire disposed on the dielectric block and connected from the first antenna patch to a surface having the same potential as the ground surface, an RF switching stage disposed on the dielectric block, connected to the first antenna patch, and that provides a switching ON/OFF operation in conjunction with the RF ground wire depending on a magnitude of a local signal LO.

First claim

What is claimed is:

1 . An antenna-sub harmonic mixer block comprising:
a dielectric block disposed on a PCB substrate having a ground surface; an antenna including a first antenna patch provided on the dielectric block and having a metal patch and a slot, and a second antenna patch provided on the dielectric block, spaced apart from the first antenna patch to surround the first antenna patch, and configured to receive a ground voltage at the same potential as the ground surface of the PCB substrate; an RF ground wire disposed on the dielectric block and connected to the first antenna patch having the same potential as the ground surface; an RF switching stage disposed on the dielectric block, connected to the first antenna patch, and configured to provide a switching ON/OFF operation in conjunction with the RF ground wire depending on a magnitude of a local signal LO; an LO filter stage provided on the dielectric block, connected to the RF switching stage, and formed of a metal pattern to filter a signal received through the antenna; a local signal generator connected to the LO filter stage and configured to generate and provide the local signal LO; an IF filter stage connected to the LO filter stage in parallel with the local signal generator and formed of a metal pattern to filter signals other than a baseband signal IF; and a conductive enclosure configured to surround the dielectric block on the PCB substrate, and in which only an area vertically overlapping with the antenna is open.

2 . The antenna-sub harmonic mixer block of claim 1 , wherein the metal patch of the first antenna patch and a metal patch of the second antenna patch, which are provided on the dielectric block in the conductive enclosure are optimized in thickness, length, and spacing between metal slots to form a patch antenna in a broadband, and the patch antenna is disposed to receive a carrier wave in a terahertz band through the opened area of the conductive enclosure.

3 . The antenna-sub harmonic mixer block of claim 1 , wherein, when viewed from a node of the RF switching stage connected to the first antenna patch, the RF ground wire is configured to appear as an opened state (high impedance) with respect to a carrier wave (RF) frequency in a terahertz band, and configured to appear as an grounded state (short impedance) with respect to a frequency of the local signal LO.

4 . The antenna-sub harmonic mixer block of claim 1 , wherein the RF switching stage is configured of a single chip of an anti-parallel pair in which two Schottky barrier diodes are interlocked with each other in parallel with opposite polarities, and configured by bonding in a flip-chip state on the dielectric block.

5 . The antenna-sub harmonic mixer block of claim 4 , wherein the RF switching stage is:
configured to provide a switching ON/OFF operation in conjunction with the RF ground wire with respect to the local signal LO generated by the local signal generator and input to the RF switching stage through the LO filter stage, and configured to be turned on twice in one period of the local signal LO by switching ON when a strength of the local signal LO is greater than an absolute value of a threshold voltage Vth of the Schottky barrier diode and by switching OFF when the strength of the local signal LO is less than the absolute value of the threshold voltage Vth of the Schottky barrier diode.

6 . The antenna-sub harmonic mixer block of claim 1 , wherein the LO filter stage and IF filter stage are configured to have low pass filter characteristics,
wherein the LO filter stage attenuates and filters an RF signal input through the antenna and passes the local signal LO and the baseband signal IF, and wherein the IF filter stage passes only the baseband signal IF and attenuates and filters all other high frequency signals (the RF signal and the local signal LO).

7 . The antenna-sub harmonic mixer block of claim 6 , wherein the LO filter stage and IF filter stage form a circuit by configuring a capacitor and inductor with conductive microstrip stub lines.

8 . The antenna-sub harmonic mixer block of claim 1 , wherein the local signal generator is composed of a frequency multiplier and amplifier to receive a high-purity reference sine wave signal having a low frequency from the outside and to obtain a desired frequency and signal strength.

9 . An image scanner comprising a transmitting cluster, a receiving cluster, and a scanning module, and
wherein the receiving cluster includes antenna-sub harmonic mixer blocks in a form of a plurality of arrays disposed on a PCB substrate having the same ground surface and a conductive enclosure surrounding the antenna-sub harmonic mixer blocks, and wherein each of the antenna-sub harmonic mixer blocks includes: a dielectric block disposed on the PCB substrate having the ground surface; an antenna including a first antenna patch provided on the dielectric block and having a metal patch and a slot, and a second antenna patch provided on the dielectric block, spaced apart from the first antenna patch to surround the first antenna patch, and configured to receive a ground voltage at the same potential as the ground surface of the PCB substrate; an RF ground wire disposed on the dielectric block and connected from the first antenna patch to a surface having the same potential as the ground surface; an RF switching stage disposed on the dielectric block, connected to the first antenna patch, and configured to provide a switching ON operation or a switching OFF operation in conjunction with the RF ground wire depending on a magnitude of a local signal LO; an LO filter stage provided on the dielectric block, connected to the RF switching stage, and formed of a metal pattern to filter a signal received through the antenna; a local signal generator connected to the LO filter stage and configured to generate and provide the local signal LO; and an IF filter stage connected to the LO filter stage in parallel with the local signal generator and formed of a metal pattern to filter signals other than a baseband signal; and wherein the conductive enclosure configured to surround the dielectric block on the PCB substrate, and in which only an area vertically overlapping with the antenna is open.

10 . The image scanner of claim 9 , wherein the metal patch of the first antenna patch and a metal patch of the second antenna patch, which are provided on the dielectric block in the conductive enclosure are optimized in thickness, length, and spacing between metal slots to form a patch antenna in a broadband, and the patch antenna is disposed to receive a carrier wave in a terahertz band through the opened area of the conductive enclosure.

11 . The image scanner of claim 9 , wherein, when viewed from a node of the RF switching stage connected to the first antenna patch, the RF ground wire is configured to appear as an opened state (high impedance) with respect to a carrier wave (RF) frequency in a terahertz band, and configured to appear as a grounded state (short impedance) with respect to a frequency of the local signal LO.

12 . The image scanner of claim 9 , wherein the RF switching stage is configured of a single chip of an anti-parallel pair in which two Schottky barrier diodes are interlocked with each other in parallel with opposite polarities, and configured by bonding in a flip-chip state on the dielectric block.

13 . The antenna-sub harmonic mixer block of claim 12 , wherein the RF switching stage is:
configured to provide a switching ON/OFF operation in conjunction with the RF ground wire with respect to the local signal LO generated by the local

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Kim Young Ho
• Park Kyung Hyun
• Park Dong Woo
• Shin Jun-Hwan
• Lee Il Min

Classifications

• H01Q9/0407

  Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40) · CPC title

• H01Q1/48

  Earthing means; Earth screens; Counterpoises · CPC title

• H03D7/02

  by means of diodes (H03D7/14 - H03D7/22 take precedence) · CPC title

• G01N22/00 Primary

  Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more (G01N3/00 - G01N17/00, G01N24/00 take precedence) · CPC title

• H10D8/80

  PNPN diodes, e.g. Shockley diodes or break-over diodes · CPC title