CA-3237298-C - RADIO FREQUENCY SWITCH DRIVER

Abstract

An RF switching circuit for switching RF signals, the RF switching circuit comprises one or more RF switch drivers and one or more RF switches, the RF switch drivers configured to drive the one or more RF switches by supplying power to the one or more RF switches, the RF switch driver comprising an isolated gate driver comprising one or more inputs, one or more outputs, and electrical separation between the input circuitry and the output circuitry of the isolated gate driver, the RF switch driver configured to receive an input signal indicating when the one or more RF switches should be turned on and/or off, and to send in response an appropriate signal at the appropriate voltage to the one or more RF switches to turn them on or off according to the input signal.

Inventors

• Sergei Ossif

Assignees

• ICEYE OY

Dates

Publication Date

20260505

Application Date

20221108

Priority Date

20211116

Claims (20)

1. 17 Claims: 1. A system for switching one or more antennas between transmit and receive modes, the system comprising: for each of the one 5 or more antennas: a power amplifier and a low-noise amplifier arranged to amplify RF signals during the transmit and receive modes of the antenna respectively; and a RF switching circuit, wherein the RF switching circuit comprises one or more RF switches, each of the one or more RF switches comprising a first RF switch 10 element arranged to connect the power amplifier to the antenna during the transmit mode and a second RF switch element arranged to connect the low-noise amplifier to the antenna during the receive mode; the system further comprising: a first RF switch driver connected to each first RF switch element of the one 15 or more RF switches for driving the one or more RF switches during the respective transmit modes of the one or more antennas, and a second RF switch driver connected to each second RF switch element of the one or more RF switches for driving the one or more RF switches during the respective receive modes of the one or more antennas, wherein each of the first and second RF switch drivers comprises 20 an isolated gate driver arranged to receive a periodic switching signal.
2. 2. The system according to claim 1, wherein the first and second RF switch drivers further comprise a power switch connected to the output of the isolated gate driver for periodically supplying voltage to the one or more RF switches to drive the 25 one or more RF switches.
3. 3. The system according to claim 2, wherein the power switch comprises a Pchannel (PMOS) MOSFET and an N-channel (NMOS) MOSFET. 30
4. 4. The system according to any one of claims 1 to 3, wherein the first and second RF switch drivers further comprise an adjustable dead-time generator connected to an input of the isolated gate driver, wherein the adjustable dead-time generator is configured to cause a delay in switching of the one or more switches. 35
5. 5. The system according to claim 4, wherein the adjustable dead-time generator comprises a plurality of multiplexers. 18
6. 6. The system according to claim 5, wherein the multiplexers comprise 4-1 multiplexers.
7. 7. The system according to claim 5 or claim 6 comprising two multiplexers.
8. 8. The system according to claim 7 wherein at least one of the RF switches comprises a RF PIN diode switch.
9. 9. The system according to claim 7 or 8 wherein at least one of the RF switches comprises one of a SPDT RF switch, a DPDT RF switch, and 10 a SPST RF switch.
10. 10. The system of any one of claims 1 to 9, wherein the first and second RF switch drivers are each connected to a plurality of RF switches. 15
11. 11. The system of any one of claims 1 to 10, wherein each antenna comprises a phased array antenna.
12. 12. The system according to claim 11, wherein the phased array antenna comprises a synthetic aperture radar antenna.
13. 13. The system of any one of claims 1 to 12, wherein each antenna is mounted on a satellite.
14. 14. The system of any one of claims 1 to 13, wherein the antenna comprises an 25 antenna configured for synthetic aperture radar imaging.
15. 15. The system of any one of claims 1 to 14, wherein the first and second RF switch drivers further comprise a power switch connected to the isolated gate driver for periodically supplying voltage to the one or more RF switches to drive the one or 30 more RF switches.
16. 16. The system of any one of claims 1 to 15, wherein the system further comprises a power amplifier driver for and connected to each power amplifier, wherein the power amplifier driver is configured to receive a transmit/receive pulse to 35 drive the power amplifier.
17. 17. The system of any one of claims 1 to 16, wherein the system further comprises a low-noise amplifier driver for and connected to each low-noise amplifier, 19 wherein the low noise amplifier driver is configured to receive a transmit/receive pulse to drive the low-noise amplifier.
18. 18. The system of any one of claims 1 to 17, wherein the system further comprises a RF divider for and connected to each power amplifier 5 for delivering a signal to the power amplifier.
19. 19. The system of any one of claims 1 to 18, wherein the system further comprises a RF combiner for and connected to each low-noise amplifier for receiving 10 a signal from the low-noise amplifier.
20. 20. The system according to claim 1 wherein the first and second RF switch elements each comprise PIN diodes. 15

Description

RADIO FREQUENCY SWITCH DRIVER [0001] The present invention relates to a radio frequency (RF) switch driver, and an RF 5 switching circuit for switching one or more antennas between receive and transmit modes. The invention also relates to a method of driving one or more RF switches, as well as a method for switching the state of one or more antennas. Background [0002] Radio frequency (RF) switches, sometimes known as microwave switches, are used for routing high-frequency signals through many different types of circuits. RF switches can be electro-mechanical switches, or solid-state switches based on semi-conductor technology. Solid state switches function similarly to electro-mechanical switches but contain no moving 15 parts. Instead, they may contain solid-state devices such as MOSFETS (Metal Oxide Semiconducting Field Effect Transistors) and/or PIN (positive-intrinsic-negative) diodes. PIN diodes comprise an area of intrinsic (I) or undoped semiconducting material sandwiched in between N-doped and P-doped regions. For high-frequency signals, they essentially act as variable-resistors, with the impedance depending on the bias applied. In the "off' state, the 20 PIN diode essentially acts as an open circuit to a RF signal, whereas in the "on" state the PIN diode has a low impedance, sometimes as low as 1 Ohm, thereby allowing the highfrequency signal to be passed through. PIN diodes are well known in the art to be suitable for RF switches due these characteristics along with their relatively fast switching times relative to electro-mechanical switches. [0003] RF switches can be used in conjunction with power amplifiers in various RF circuits. Power amplifiers (PAs) are used in a variety of applications to amplify RF signals delivered to electronic components,. Such components may include but are not limited to antennas such as those used in satellite communications. Antennas may be phased array antennas, which 30 comprise multiple antenna elements to allow for beam steering, for example. In antennas that are used for both transmitting and receiving signals, one amplifier might be dedicated to amplifying the transmit signal being sent to an antenna, and another amplifier such as a lownoise amplifier (LNA) may be used for amplifying the signal that is received by the same antenna. CA 03237298 2024-5-3 [0004] RF frequencies typically refer to any signal than can be transmitted or received by an antenna, ranging from about 30 KHz to 300 GHz, or even from 30 Hz to 300 GHz if ultra-low frequency radio waves are included. WO 2023/088727 PCT /EP2022/081081 [0005] Many PA boards for operating antennas that both transmit and receive RF signals utilize a common architecture, where the antenna is connected to an RF switch that commutes between the power amplifier (PA) and the low noise amplifier (LNA) during the 5 transmit and receive phases respectively. An example is shown in UK patent application GB2578926A. The RF switch is controlled by applying voltages of different polarities to its inputs. As such, a RF switch driver circuit is required to apply the correct voltage to the inputs of the RF switch at the correct times. These RF switch driver circuits can be complicated, requiring many different components and multiple voltage sources. They also need to be able 10 to drive the RF switch so that it switches very quickly while avoiding any short circuits in the RF switch. In some implementations the length of a regular transmil/receive (Tx/Rx) pulse for a given antenna circuit can be between 100μs and 250μs, which means the RF switch needs to switch between the PA and LNA very fast. Even with the use of Pl N diodes, the combination of the RF switch driver and the RF switch can still be the slowest part of the 15 whole switching circuit, with switching times of around 460 ns. [0006] The embodiments of the invention described below are not limited to implementations which solve any or all of the disadvantages of the known approaches described above. 20 Summary [0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter; variants and alternative 25 features which facilitate the working of the invention and/or serve to achieve a substantially similar technical effect should be considered as falling into the scope of the invention disclosed herein. [0008] In a first aspect, the present disclosure provides a RF switch driver for driving one or more RF switches by supplying power to the one or more RF switches, the RF switch driver 30 comprising an isolated gate driver. Thus in one aspect an isolated gate driver is used in a context very different from the intended uses of isolated gate drivers. [0009] The RF switch driver may be arranged to re