Wireless circuit with optical frequency detection

Abstract

The invention relates to a wireless circuit with optical frequency detection. An electronic device is provided with a wireless circuit. The wireless circuitry includes an optical mixer, a first laser and a second laser coupled to the optical mixer through a first optical path and a second optical path, a first optical resonator along the first optical path, a second optical resonator along the second optical path, and a third optical resonator along the second optical path. A phase-locked loop coupling the optical mixer to the first optical resonator; and a frequency-locked loop coupling an optical mixer to the second optical resonator. The first optical resonator and the second optical resonator may have optical resonant combs with different comb pitches, and the first laser and the second laser may be injection-locked. Once injection-locked, a control circuit may estimate the frequency of the optical signals output by the first laser and the second laser based on the beat frequency signal output by the optical mixer and based on the comb pitch of the first optical resonator and the second optical resonator. The wireless circuitry may perform or adjust wireless communications based on the estimated frequency.

Description

[0001] This application claims priority to U.S. Patent Application No. 19 / 184,958, filed April 21, 2025, and U.S. Provisional Patent Application No. 63 / 644,614, filed May 9, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates in general to electronic devices, including electronic devices having wireless circuitry. Background Technology

[0003] Electronic devices may be equipped with wireless capabilities. Wireless-capable electronic devices have wireless circuitry including one or more antennas. The wireless circuitry is used to perform communication using radio frequency signals transmitted by the antennas.

[0004] As software applications on electronic devices become increasingly data-intensive over time, the need for electronic devices that can support wireless communication at higher data rates has increased. However, the maximum data rate supported by electronic devices is limited by the frequency of the radio frequency signal. As the communication frequency increases, it can become difficult to provide a low phase noise clock to the wireless circuit. Summary of the Invention

[0005] The electronic device may include a wireless circuit. The wireless circuit may include an optical mixer, a first laser coupled to the optical mixer via a first optical path, and a second laser coupled to the optical mixer via a second optical path. The first laser may transmit a first optical local oscillator (LO) signal onto the first optical path. The second laser may transmit a second optical LO signal onto the second optical path. The optical mixer may be coupled to an antenna element. The optical mixer may generate a current on the antenna element based on the first and second optical LO signals.

[0006] The wireless circuit may include loop paths around the first laser and the second laser. These loop paths minimize phase noise and jitter in both the first and second lasers. For example, the wireless circuit may include a first optical resonator optically coupled to the first optical path. The wireless circuit may include a second optical resonator optically coupled to the second optical path. The wireless circuit may include a frequency-locked loop (FLL) coupling the electrical output of the optical mixer to the first optical resonator. The wireless circuit may include a phase-locked loop (PLL) coupling the electrical output of the optical mixer to the second optical resonator. The first optical resonator may exhibit a first optical resonant comb with a first comb spacing. The first optical resonator may be injection-locked to the first laser. The second optical resonator may exhibit a second optical resonant comb with a second comb spacing. The second optical resonator may be injection-locked to the second laser.

[0007] Once the laser is injected and locked, the control circuitry can estimate the frequencies of the first and second optical LO signals based on the electrical beat frequency signal output from the optical mixer. For example, the control circuitry can detect the first and second comb pitches based on changes in the electrical beat frequency signal. The control circuitry can estimate the first and second frequencies based on the first and second comb pitches and the beat frequency of the electrical beat frequency signal. To resolve ambiguities in the estimated first and second frequencies, the first and second comb pitches can be different. The first and second comb pitches can, for example, have a greatest common divisor less than or equal to a predetermined threshold (e.g., 2 MHz to 15 MHz or another frequency depending on the frequency range of the optical local oscillator and the comb pitch).

[0008] One aspect of this disclosure provides a wireless circuit. The wireless circuit may include a first laser. The wireless circuit may include an antenna element. The wireless circuit may include an optical mixer coupled to the antenna element. The wireless circuit may include a first optical path coupling the first laser to the optical mixer, the first laser being configured to output a first optical local oscillator (LO) signal to the first optical path. The wireless circuit may include a first optical resonator optically coupled to the first optical path. The wireless circuit may include a phase-locked loop (PLL) coupling the electrical output of the optical mixer to the first optical resonator.

[0009] One aspect of this disclosure provides an electronic device. The electronic device may include a first laser. The electronic device may include an antenna element. The electronic device may include an optical mixer coupled to the antenna element. The electronic device may include a first optical path coupling the first laser to the optical mixer, the first laser being configured to output a first optical local oscillator (LO) signal to the first optical path. The electronic device may include a first optical resonator optically coupled to the first optical path. The electronic device may include a frequency-locked loop (FLL) coupling the electrical output of the optical mixer to the first optical resonator.

[0010] One aspect of this disclosure provides a method for operating a wireless circuit in an electronic device. The method may include transmitting a first optical local oscillator (LO) signal at a first frequency to an optical mixer via a first optical path using a first laser. The method may include transmitting a second optical LO signal at a second frequency to the optical mixer via a second optical path using a second laser. The method may include generating an electrical signal based on the first and second optical LO signals using the optical mixer. The method may include injecting and locking the first laser using a first optical resonator optically coupled to the first optical path based on the electrical signal, wherein the first optical resonator exhibits a first optical resonant comb having a first comb spacing. The method may include injecting and locking the second laser using a second optical resonator optically coupled to the second optical path based on the electrical signal, wherein the second optical resonator exhibits a second optical resonant comb having a second comb spacing different from the first comb spacing. The method may include using processing circuitry to estimate the first and second frequencies based on the frequency of the electrical signal, the first comb spacing, and the second comb spacing. Attached Figure Description

[0011] Figure 1 It is a block diagram of an exemplary electronic device with wireless circuitry according to some implementation schemes.

[0012] Figure 2 This is a top view of an example wireless circuit configured to transmit wireless signals at frequencies greater than approximately 100 GHz based on an optical local oscillator (LO) signal, according to some implementation schemes.

[0013] Figure 3 This illustrates some implementation schemes. Figure 2 A top view showing how an exemplary wireless circuit of the type shown can convert a received wireless signal at a frequency greater than about 100 GHz into an intermediate frequency signal based on an optical LO signal.

[0014] Figure 4 This illustrates some implementation schemes. Figure 2 and Figure 3 A top view showing how wireless circuits of the type shown can be stacked to cover multiple polarizations.

[0015] Figure 5 This demonstrates how, according to some implementation schemes, it is possible to... Figure 4 A top view showing a wireless circuit of the type shown integrated into a phased antenna array for transmitting wireless signals at frequencies greater than approximately 100 GHz.

[0016] Figure 6 This is a circuit diagram of an exemplary wireless circuit that uses optical LO signals generated by a first laser and a second laser to transmit radio frequency signals at frequencies greater than about 100 GHz, according to some implementation schemes.

[0017] Figure 7 This illustrates some implementation schemes. Figure 6 The diagram illustrates how an exemplary wireless circuit of the type shown can be configured with a circuit for detecting the frequency of an optical LO signal.

[0018] Figure 8 This illustrates some implementation schemes. Figure 7 A graph illustrating the exemplary resonant response of an optical resonator in a wireless circuit of the type shown.

[0019] Figure 9 It is based on the use of some implementation plans. Figure 6 and Figure 7 A flowchart illustrating the exemplary operations involved in wireless communication performed by a wireless circuit of the type shown. Detailed Implementation

[0020] Figure 1 The electronic device 10 (sometimes referred to herein as electro-optical device 10) may be: a computing device, such as a laptop computer, desktop computer, computer monitor containing an embedded computer, tablet computer, cellular phone, media player, or other handheld or portable electronic device; a smaller device, such as a wristwatch, a hanging device, a headset or handset, a device embedded in glasses, goggles; or other equipment worn on the user's head; or other wearable or micro-devices, televisions, computer monitors (without an embedded computer), gaming devices, navigation devices, embedded systems (such as systems in which electronic equipment with a display is installed in a kiosk or vehicle), voice-controlled speakers connected to the wireless Internet, home entertainment devices, remote control devices, game controllers, peripheral user input devices, wireless base stations or access points, equipment that enables the functions of two or more of these devices; or other electronic equipment.

[0021] like Figure 1 As shown in the functional block diagram, device 10 may include components located on or within an electronic device housing, such as housing 12. Housing 12 (sometimes referred to as a shell) may be formed of plastic, glass, ceramic, fiber composite material, metal (e.g., stainless steel, aluminum, metal alloys, etc.), other suitable materials, or combinations thereof. In some cases, housing 12 may be partially or entirely formed of dielectric or other low-conductivity materials (e.g., glass, ceramic, plastic, sapphire, etc.). In other cases, housing 12, or at least some of the structures constituting housing 12, may be formed of metallic elements.

[0022] Device 10 may include control circuitry 14. Control circuitry 14 may include storage devices, such as storage circuitry 16. Storage circuitry 16 may include hard disk drive storage devices, non-volatile memory (e.g., flash memory configured to form a solid-state drive or other electrically programmable read-only memory), volatile memory (e.g., static random access memory or dynamic random access memory), etc. Storage circuitry 16 may include storage devices and / or removable storage media integrated within device 10.

[0023] Control circuitry 14 may include processing circuitry, such as processing circuitry 18. Processing circuitry 18 may be used to control the operation of device 10. Processing circuitry 18 may include one or more processors, such as a microprocessor, microcontroller, digital signal processor, host processor, baseband processor integrated circuit, application-specific integrated circuit, central processing unit (CPU), graphics processing unit (GPU), etc. Control circuitry 14 may be configured to perform operations in device 10 using hardware (e.g., dedicated hardware or circuitry), firmware, and / or software. Software code for performing operations in device 10 may be stored on storage circuitry 16 (e.g., storage circuitry 16 may include a non-transitory (tangible) computer-readable storage medium storing software code). This software code may sometimes be referred to as program instructions, software, data, commands, or code. The software code stored on storage circuitry 16 may be executed by processing circuitry 18.

[0024] Control circuitry 14 can be used to run software on device 10, such as satellite navigation applications, internet browsing applications, Voice over Internet Protocol (VoIP) telephone calling applications, email applications, media playback applications, operating system functions, etc. To support interaction with external equipment, control circuitry 14 can be used to implement communication protocols. Communication protocols that can be implemented using control circuitry 14 include Internet Protocol, Wireless Local Area Network (WLAN) protocols (e.g., IEEE 802.11 protocol—sometimes referred to as...). ), such as Protocols such as those used for other short-range wireless communication links, including protocols such as other Wireless Personal Area Network (WPAN) protocols, IEEE 802.11ad protocols (e.g., ultra-wideband protocols), cellular phone protocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP fifth-generation (5G) new radio (NR) protocols, sixth-generation (6G) protocols, sub-THz protocols, THz protocols, etc.), antenna diversity protocols, satellite navigation system protocols (e.g., Global Positioning System (GPS) protocols, Global Navigation Satellite System (GLONASS) protocols, etc.), antenna-based spatial ranging protocols, optical communication protocols, or any other desired communication protocol. Each communication protocol may be associated with a corresponding Radio Access Technology (RAT), which specifies the physical connection method used to implement the protocol.

[0025] Device 10 may include input-output circuitry 20. Input-output circuitry 20 may include input-output devices 22. Input-output devices 22 may be used to allow data to be supplied to device 10 and to allow data to be supplied from device 10 to external devices. Input-output devices 22 may include user interface devices, data port devices, and other input-output components. For example, input-output devices 22 may include touch sensors, displays (e.g., touch-sensitive displays and / or force-sensitive displays), light-emitting components such as displays without touch sensor capability, buttons (mechanical, capacitive, optical, etc.), scroll wheels, touchpads, keypads, keyboards, microphones, cameras, buttons, speakers, status indicators, audio jacks and other audio port components, digital data port devices, motion sensors (accelerometers, gyroscopes, and / or compasses for detecting motion), capacitive sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), temperature sensors, etc. In some configurations, keyboards, headphones, displays, pointing devices such as touchpads, mice and joysticks, and other input-output devices may be coupled to device 10 via wired or wireless connections (e.g., some of the input-output devices 22 may be peripherals coupled to the main processing unit or other parts of device 10 via wired or wireless links).

[0026] Input-output circuitry 20 may include wireless circuitry 24 to support wireless communication. Wireless circuitry 24 (sometimes referred to herein as wireless communication circuitry 24) may include one or more antennas 30 (e.g., antenna elements). Wireless circuitry 24 may also include transceiver circuitry 26. Transceiver circuitry 26 may include transmitter circuitry, receiver circuitry, modulator circuitry, optical mixer, demodulator circuitry (e.g., one or more modems), radio frequency circuitry, one or more radio components, intermediate frequency circuitry, optical transmitter circuitry, optical receiver circuitry, optical light source, other optical components, baseband circuitry (e.g., one or more baseband processors), amplifier circuitry, clock circuitry such as one or more local oscillators and / or phase-locked loops, memory, one or more registers, filter circuitry, switching circuitry, analog-to-digital converter (ADC) circuitry, digital-to-analog converter (DAC) circuitry, radio frequency transmission line, optical fiber, and / or any other circuitry for transmitting and / or receiving wireless signals using antenna 30. The components of transceiver circuit 26 may be implemented on an integrated circuit, chip, system-on-a-chip (SOC), die, printed circuit board, substrate, or package, or the components of transceiver circuit 26 may be distributed across two or more integrated circuits, chips, SOCs, printed circuit boards, substrates, and / or packages.

[0027] Figure 1 The examples are illustrative and not restrictive. Although for clarity, in Figure 1 In the example, control circuitry 14 is shown separate from wireless circuitry 24, but wireless circuitry 24 may include processing circuitry (e.g., one or more processors) and / or storage circuitry, the processing circuitry forming part of processing circuitry 18, and the storage circuitry forming part of storage circuitry 16 of control circuitry 14 (e.g., portions of control circuitry 14 may be implemented on wireless circuitry 24). As an example, control circuitry 14 may include baseband circuitry (e.g., one or more baseband processors), digital control circuitry, analog control circuitry, and / or other control circuitry forming part of wireless circuitry 24. Baseband circuitry may, for example, access the communication protocol stack on control circuitry 14 (e.g., storage circuitry 20) to: perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and / or PDU layer; and / or perform control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and / or non-access layer.

[0028] Transceiver circuitry 26 can be coupled to each antenna 30 in wireless circuitry 24 via a corresponding signal path 28. Each signal path 28 may include one or more RF transmit lines, waveguides, optical paths, optical fibers, optical waveguides, and / or any other desired line / path for transmitting wireless signals between transceiver circuitry 26 and antenna 30. Antenna 30 may be formed using any desired antenna structure for transmitting wireless signals. For example, antenna 30 (e.g., antenna element) may include a resonant element (radiator) formed from a dipole antenna structure, a planar dipole antenna structure (e.g., a butterfly antenna structure), a slot antenna structure, a loop antenna structure, a patch antenna structure, an inverted F-shaped antenna structure, a planar inverted F-shaped antenna structure, a helical antenna structure, a monopole antenna, a dipole, a hybrid of these designs, or any other antenna type. Filter circuitry, switching circuitry, impedance matching circuitry, and / or other antenna tuning components may be adjusted to modify the frequency response and wireless performance of antenna 30 over time.

[0029] If desired, two or more antennas in antenna 30 may be integrated into a phased antenna array (sometimes referred to herein as a phased array antenna), in which each antenna transmits a wireless signal having a corresponding phase and magnitude adjusted over time, such that the wireless signals interfere constructively and destructively to generate (form) a signal beam in a given pointing direction. As used herein, the term “transmitting a wireless signal” means the transmission and / or reception of a wireless signal (e.g., for performing one-way and / or two-way wireless communication with an external wireless communication device). Antenna 30 may transmit a wireless signal by radiating the signal into free space (or radiating it into free space through an intermediary device structure such as a dielectric overlay). Alternatively or in addition, antenna 30 may receive a wireless signal from free space (e.g., through an intermediary device structure such as a dielectric overlay). The transmission and reception of wireless signals by antenna 30 each involve the excitation or resonance of a current on the antenna resonant (radiating) element in the antenna by a signal within the antenna's operating frequency band.

[0030] Transceiver circuitry 26 may use antenna 30 to transmit and / or receive wireless signals that transmit wireless communication data between device 10 and external wireless communication equipment (e.g., one or more other devices, such as device 10, a wireless access point, or a base station). Wireless communication data may be transmitted bidirectionally or unidirectionally. Wireless communication data may include, for example, data encoded into corresponding data symbols, packets, datagrams, and / or frames, such as wireless data associated with telephone calls, streaming media content, internet browsing, wireless data associated with software applications running on device 10, email messages, etc.

[0031] Alternatively, wireless circuitry 24 may use antenna 30 to perform wireless sensing operations. Sensing operations may allow device 10 to detect (e.g., sense or identify) the presence, location, orientation, and / or velocity (motion) of objects external to device 10 (e.g., using a radar scheme or another spatial ranging scheme). Control circuitry 14 may use the detected presence, location, orientation, and / or velocity of the external object to perform any desired device operation. As an example, control circuitry 14 may use the detected presence, location, orientation, and / or speed of an external object to identify corresponding user input for one or more software applications running on device 10, such as gesture input performed by the user's hand or other body parts or by an external stylus, game controller, headset, or other peripheral device or accessory; determine when one or more antennas 30 need to be disabled or set with a reduced maximum transmit power level (e.g., to meet regulatory restrictions on radio frequency exposure); determine how to guide (form) the radio frequency signal beam generated by antennas 30 for wireless circuitry 24 (e.g., in the case where antennas 30 include a phased array of antennas 30); map or model the environment around device 10 (e.g., to generate a software model of the room where device 10 is located for use by augmented reality applications, gaming applications, mapping applications, home design applications, engineering applications, etc.); detect the presence of obstacles near (e.g., around) device 10 or in the direction of movement of the user of device 10; etc.

[0032] Wireless circuit 24 can transmit and / or receive wireless signals within a corresponding frequency band of the electromagnetic spectrum (sometimes referred to herein as the communication band or simply the "band"). The frequency band processed by wireless circuit 24 may include the wireless local area network (WLAN) band (e.g., (IEEE 802.11) or other WLAN communication bands), such as the 2.4 GHz WLAN band (e.g., 2400 MHz to 2480 MHz), the 5 GHz WLAN band (e.g., 5180 MHz to 5825 MHz), 6E band (e.g., 5925MHz to 7125MHz) and / or others Frequency bands (e.g., 1875MHz to 5160MHz); Wireless Personal Area Network (WPAN) frequency bands, such as 2.4GHz. Frequency bands or other WPAN communication bands; cellular telephone bands (e.g., bands from about 600 MHz to about 5 GHz, 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) band below 10 GHz, 5G New Radio Frequency Range 2 (FR2) band between 20 GHz and 60 GHz, etc.); other centimeter or millimeter wave bands (e.g., between 10 GHz and 300 GHz); near-field communication bands (e.g., 13.56 MHz); satellite navigation bands (e.g., GPS bands from 1565 MHz to 1610 MHz, Global Navigation Satellite System (GLONASS) bands, BeiDou Navigation Satellite System (BDS) bands, etc.); ultra-wideband (UWB) bands operating under the IEEE 802.15.4 protocol and / or other ultra-wideband communication protocols; communication bands under the 3GPP wireless communication standard family; communication bands under the IEEE 802.XX standard family, and / or any other desired bands of interest.

[0033] Over time, software applications on electronic devices such as Device 10 have become increasingly data-intensive. Therefore, the wireless circuitry on these devices needs to support data transmission at increasingly higher data rates. Generally, the data rate supported by a wireless circuit is proportional to the frequency of the wireless signal transmitted by the circuit (e.g., higher frequencies support higher data rates compared to lower frequencies). Wireless circuit 24 can transmit centimeter and millimeter wave signals to support relatively high data rates (e.g., because centimeter and millimeter wave signals correspond to relatively high frequencies between approximately 10 GHz and 300 GHz). However, the data rates supported by centimeter and millimeter wave signals may still be insufficient to meet all the data transmission needs of Device 10. To support even higher data rates, such as up to 5 Gbps-10 Gbps or higher, wireless circuit 24 can transmit wireless signals at frequencies greater than approximately 100 GHz.

[0034] like Figure 1As shown, wireless circuit 24 can transmit wireless signals 32 at frequencies greater than approximately 100 GHz (sometimes referred to as extremely high frequency (THF) frequencies) and can receive wireless signals 34 at the same frequencies. Wireless signals 32 and 34 may be referred to herein as THF signals 32 and 34, sub-THz signals 32 and 34, THz signals 32 and 34, or submillimeter wave signals 32 and 34. THF signals 32 and 34 may be at frequencies below THz or THz frequencies, such as between 100 GHz and 1 THz, between 100 GHz and 10 THz, between 100 GHz and 2 THz, between 200 GHz and 1 THz, between 300 GHz and 1 THz, between 300 GHz and 2 THz, between 300 GHz and 10 THz, between 100 GHz and 800 GHz, between 200 GHz and 1.5 THz, etc. (e.g., below THz, THz, THF, or submillimeter bands, such as 3GPP sixth generation (6G) bands).

[0035] The high data rates supported by these frequencies can be utilized by device 10 to perform cellular phone voice and / or data communications (e.g., simultaneously supporting spatial multiplexing to provide additional data bandwidth), to perform spatial ranging operations such as radar operations to detect the presence, location, and / or speed of objects outside device 10, to perform vehicle sensing (e.g., with enhanced security), to perform health / body monitoring of the user of device 10 or another person, to perform gas or chemical detection, to establish a high data rate wireless connection between device 10 and another device or peripheral device (e.g., to establish a high data rate connection between a display driver on device 10 and a display showing ultra-high resolution video), to establish a remote wireless head (e.g., a flexible high data rate connection), to establish a THF chip-to-chip connection supporting high data rates within device 10 (e.g., where an antenna 30 on a first chip in device 10 transmits a THF signal 32 to another antenna 30 on a second chip in device 10), and / or to perform any other desired high data rate operations.

[0036] Wireless circuitry 24 may include one or more antennas 30 for transmitting THF signals (e.g., at frequencies greater than about 100 GHz), and / or may include one or more antennas 30 for transmitting non-THF signals (e.g., at frequencies less than about 100 GHz). Transceiver circuitry 26 may include clock circuitry for generating one or more clock signals (e.g., local oscillator signals). Transceiver 26 may use the clock signals to transmit and / or receive signals (e.g., THF signals and / or non-THF signals).

[0037] A clock signal may be provided as an input to one or more mixers in transceiver circuitry 26 for signal conversion between different frequencies (e.g., between baseband, intermediate frequency, radio frequency, optical frequency, etc.). The mixers may include one or more radio mixers (e.g., for conversion between radio frequency, intermediate frequency, and / or baseband frequencies) and / or one or more electro-optical (EO) mixers (e.g., for conversion between radio frequency and optical frequencies or between optical frequencies). EO mixers may be referred to herein as optical mixers and may include photodiodes (e.g., single-row carrier photodiodes (UTC PDs)), electro-optic modulators (e.g., Mach-Zehnder modulators), and / or other mixers that convert signals from radio frequency to optical frequency and / or from optical frequency to radio frequency. For example, transceiver circuitry 26 may use a radio mixer to transmit non-THF signals, while one or both of the radio mixer and the EO mixer may be used to transmit THF signals. If necessary, the clock circuit in transceiver circuit 26 may include one or more phase-locked loops (PLLs), frequency-locked loops (FLLs), self-injected lock-in (SIL) loops, and / or other circuitry for processing clock signals generated by the clock circuitry (e.g., for phase-locking, frequency-locking, self-injecting, etc. of clock signals).

[0038] Specific implementations of wireless circuit 24 using electro-optical circuitry to transmit THF signals are described herein as examples. In these implementations, wireless circuit 24 is sometimes referred to herein as electro-optical (EO) wireless circuit 24 (e.g., having one or more EO transceivers in transceiver circuitry 26). However, in general, wireless circuit 24 may transmit non-THF signals in addition to or in lieu of THF signals. In specific implementations of wireless circuit 24 transmitting THF signals, a different antenna 30 than that used to receive THF signal 34 may be used to transmit THF signal 32. However, space is very valuable within electronic devices such as device 10. Handling the transmission of THF signal 32 and the reception of THF signal 34 using different antennas 30 could consume excessive space and other resources within device 10, as two antennas 30 and signal path 28 would be required to handle both transmission and reception. To minimize space and resource consumption within device 10, the same antenna 30 and signal path 28 can be used for both transmitting THF signal 32 and receiving THF signal 34. If needed, the multiple antennas 30 in the wireless circuit 24 can transmit THF signals 32 and receive THF signals 34. If needed, the antennas can be integrated into a phased antenna array that transmits THF signals 32 and receives THF signals 34 in the corresponding signal beam oriented in the selected beam pointing direction.

[0039] Integrating components into the wireless circuitry 24 that supports wireless communication at these high frequencies can be challenging. If desired, the transceiver circuitry 26 and signal path 28 may include optical components that transmit optical signals to support the transmission of THF signal 32 and the reception of THF signal 34 in a space- and resource-efficient manner. The optical signals can be used to transmit THF signal 32 at the THF frequency and to receive THF signal 34 at the THF frequency.

[0040] Figure 2 It can be configured to use optical signals (e.g., for...) Figure 1 A diagram of an exemplary wireless circuit 35 for transmitting THF signal 32 and / or receiving THF signal 34 using a corresponding antenna 30. Wireless circuit 35 may include one or more antenna radiating (resonant) elements, such as radio frequency radiators 36. Radiator 36 is sometimes also referred to herein as resonant element 36, radiating element 36, resonant element arm 36, radiating element arm 36, resonator 36, or antenna element 36. Figure 2 In the example, wireless circuit 35 includes two radiators 36. This is illustrative and not limiting. Wireless circuit 35 is not required to have two radiators 36, and may include a single radiator 36 or more than two radiators 36 if desired.

[0041] The radiator 36 includes a specific implementation of a radiating arm (sometimes referred to herein as an antenna resonant element arm, radiating element arm, or antenna arm) described herein as an example. Figures 2 to 5 For example, wireless circuit 35 is illustrated as including a planar dipole antenna (sometimes referred to as a "butterfly" antenna) having two opposing radiators 36 (e.g., butterfly arms or dipole arms) coupled to an intervening optical mixer. This is illustrative and not limiting. Radiating arms may include monopole arms, inverted F-shaped antenna arms, helical arms, or other types of radiating arms if desired. More generally, radiator 36 may include an RF radiating or resonant arm, patch, slot (e.g., in a conductive ground plane), waveguide, dielectric resonant element, loop, or any other desired antenna radiator implemented using any desired antenna resonant element architecture that transmits RF signals based on RF antenna current flowing around the periphery of the radiator. Although referred to herein as a radiator for simplicity, radiator 36 does not need to radiate (transmit) RF signals and may only receive RF signals if desired.

[0042] like Figure 2 As shown, wireless circuitry 35 may include programmable heterodyne optical mixers coupled to radiators 36 and / or coupled between these radiators, such as optical mixer (PM) 42 (sometimes referred to herein as heterodyne optical mixer 42). For device 10 ( Figure 1A given antenna 30 transmitting THF signals may include some or all of the wireless circuitry 35 (e.g., a given antenna 30 may include radiator 36 of wireless circuitry 35 but not optical mixer 42 of wireless circuitry 35, or may include both radiator 36 of wireless circuitry 35 and optical mixer 42). As an example, optical mixer 42 may be a programmable photodiode (PD). Specific implementations of programmable single-row carrier photodiodes (UTC PDs) are sometimes described herein as examples. Therefore, optical mixer 42 may sometimes be referred to herein as photodiode 42, UTC PD 42, or programmable UTC PD 42. This is illustrative and not limiting.

[0043] Generally, the optical mixer 42 may include any desired type of heterodyne-based adjustable / programmable photodiode or optical mixer that converts electromagnetic energy (e.g., light or optical energy) at two different optical frequencies (e.g., infrared, visible, and / or ultraviolet frequencies) into a current at a THF frequency on the radiator 36, and / or vice versa (e.g., where the THF frequency is the beat frequency given by the difference between the two different optical frequencies). Each radiator 36 may, for example, have a first edge at or coupled to the optical mixer 42 and a second edge opposite the first edge that is wider than the first edge (e.g., in a specific embodiment where the radiator 36 forms at least a portion of a butterfly antenna). Other radiating elements or arms may be used if desired.

[0044] Optical mixer 42 may be able to receive one or more control signals V BIAS Bias terminal 38. Control signal V BIAS This may include bias voltages provided at one or more voltage levels and / or other control signals for controlling the operation of the optical mixer 42, such as impedance adjustment control signals for adjusting the output impedance of the optical mixer 42. Control circuit 14 ( Figure 1 ) can provide control signals V with different settings (e.g., value, amplitude, etc.) (e.g., apply, supply, assert, etc.). BIAS To dynamically control (e.g., program or adjust) the operation of the optical mixer 42 over time.

[0045] For example, control signal V BIAS This can be used to control whether wireless circuit 35 transmits THF signal 32 or receives THF signal 34. When control signal V... BIAS When a bias voltage asserted at a first level or amplitude is applied, wireless circuit 35 can be configured to transmit THF signal 32. When control signal V... BIASWhen a bias voltage asserted at a second level or amplitude is included, wireless circuit 35 can be configured to receive THF signal 34. In some specific embodiments described herein as examples, the second level or amplitude is zero volts (e.g., the bias voltage can be deasserted, decoupled, or turned off to configure optical mixer 42 to receive THF signal 34) or another level or amplitude less than the first level or amplitude. Figure 2 In the example, the control signal V BIAS This includes a bias voltage asserted at a first level to configure wireless circuit 35 to transmit THF signal 32. The control signal V can also be adjusted if necessary. BIAS To control the waveform of the THF signal (e.g., as a square function, linear function, etc. that preserves the modulation of the incident light signal), gain control is performed on the signal transmitted by the wireless circuit 35, and / or the output impedance of the optical mixer 42 is adjusted.

[0046] like Figure 2 As shown, the optical mixer 42 can be optically coupled to one or more optical paths in the signal path 28. The optical paths may include, for example, optical fibers and / or waveguides. The optical mixer 42 can be connected via the signal path 28 to the transceiver circuit 26 (…). Figure 1 The transceiver circuit 26 receives optical signals (e.g., the optical path in signal path 28 can use the optical signal carried by the optical path to illuminate the optical mixer 42). The optical signal may include a first optical local oscillator (LO) signal LO1 and a second optical local oscillator signal LO2. Optical local oscillator signals LO1 and LO2 can be received by the transceiver circuit 26. Figure 1 Light source generation in ).

[0047] Optical local oscillator signals LO1 and LO2 may be located at optical wavelengths (e.g., between 400 nm and 700 nm), ultraviolet wavelengths (e.g., near-ultraviolet or extreme ultraviolet wavelengths), and / or infrared wavelengths (e.g., near-infrared, mid-infrared, or far-infrared wavelengths). Optical local oscillator signal LO2 may be offset by a wavelength offset X from optical local oscillator signal LO1. Wavelength offset X may be equal to the wavelength of the THF signal transmitted by wireless circuit 35 (e.g., between 100 GHz and 1 THz, between 100 GHz and 10 THz, between 100 GHz and 2 THz, between 300 GHz and 800 GHz, between 300 GHz and 1 THz, between 300 GHz and 400 GHz, etc.).

[0048] During signal transmission, wireless data (e.g., wireless data packets, symbols, frames, etc.) can be modulated onto an optical local oscillator signal LO2 to generate a modulated optical local oscillator signal LO2'. If desired, the optical local oscillator signal LO1 can be provided with an optical phase shift S. The signal path 28 can illuminate the optical mixer 42 with the optical local oscillator signal LO1 (plus the optical phase shift S when applied) and the modulated optical local oscillator signal LO2'. If desired, a lens or other optical component (not shown) can be inserted between the optical path in the signal path 28 and the optical mixer 42 to help focus the optical local oscillator signal onto the optical mixer 42.

[0049] Optical mixer 42 converts an optical local oscillator signal LO1 and a modulated local oscillator signal LO2' (e.g., a beat between two optical local oscillator signals) into a radio frequency current (e.g., an antenna current) that can be radiated by radiator 36 (e.g., extending along the periphery of radiator 36). In other words, optical mixer 42 can be configured to generate a current or electrical signal on radiator 36 based on the optical local oscillator signal LO1 and the modulated optical local oscillator signal LO2'. The frequency of the antenna current is equal to the frequency difference between the local oscillator signal LO1 and the modulated local oscillator signal LO2' (e.g., a frequency offset or beat frequency corresponding to wavelength offset X). The antenna current can radiate the THF signal 32 into free space. Control signal V BIAS The controllable optical mixer 42 converts the optical local oscillator signal into an antenna current on the radiator 36 (e.g., in heterodyne operation), while simultaneously modulating and thus storing the radio data on the modulated local oscillator signal LO2' (e.g., by applying a square function to the signal). The THF signal 32 can thus carry the modulated radio data for reception and demodulation by external wireless communication equipment.

[0050] Figure 3 This illustrates how wireless circuit 35 can receive THF signal 34 (e.g., when the control signal V is received). BIAS The settings from Figure 2 The diagram shows the state after the transmitter state changes to the receiver state. (See diagram below.) Figure 3 As shown, a THF signal 34 can be incident on radiator 36. The incident THF signal 34 can generate an antenna current on radiator 36 (e.g., flowing around the periphery of radiator 36). Optical mixer 42 can use an optical local oscillator signal LO1 (plus the applied optical phase shift S), an optical local oscillator signal LO2 (e.g., without modulation), and a control signal V. BIASThe received THF signal 34 is converted into a received signal (SIGRX) output to signal path 44 (e.g., in heterodyne operation) using a bias voltage asserted at a second level. In other words, optical mixer 42 can be configured to generate current or electrical signal on signal path 44 based on electrical signal or current on radiator 36 and optical local oscillator signal.

[0051] The frequency of the received signal on signal path 44 is equal to the frequency of THF signal 34 minus the difference between the frequencies of optical local oscillator signal LO1 and optical local oscillator signal LO2. As an example, the received signal SIGRX can be at a lower frequency than THF signals 32 and 34, such as intermediate frequency (FIF). The intermediate frequency FIF can be, for example, a centimeter or millimeter wave frequency between approximately 10 GHz and 100 GHz, between approximately 30 GHz and 80 GHz, or approximately 60 GHz. In other examples, the intermediate frequency FIF can be at a frequency below 10 GHz. Optical mixer 42 can modulate and store the data from THF signal 34 in the received signal SIGRX. Transceiver circuit 26 ( Figure 1 The receiver in the optical mixer 42 can demodulate the received signal SIGRX (e.g., after further downconversion) to recover wireless data from the THF signal 34. Alternatively, the optical mixer 42 can output the received signal in the optical domain (e.g., to optical path 28 or a dedicated optical receiving path).

[0052] Figure 2 and Figure 3 The wireless circuit 35 can support the transmission of a THF signal 32 with a given polarization (e.g., linear polarization such as vertical polarization) and the reception of a THF signal 34. If needed, the wireless circuit 24 ( Figure 1 It may include multiple wireless circuits 35 for covering different polarizations. Figure 4 This is a diagram illustrating an example of how wireless circuit 24 can include multiple wireless circuits 35 for covering different polarizations.

[0053] like Figure 4As shown, the wireless circuit may include a first wireless circuit 35V for covering a first polarization (e.g., a first linear polarization such as vertical polarization), and a second wireless circuit 35H for covering a second polarization different from or orthogonal to the first polarization (e.g., second linear polarizations such as horizontal polarization). Wireless circuit 35V may include an optical mixer 42, such as an optical mixer 42V coupled between a corresponding pair of radiators 36. Wireless circuit 35H may include an optical mixer 42, such as an optical mixer 42H coupled between a corresponding pair of radiators 36 that are not parallel (e.g., orthogonal) to the radiators 36 in wireless circuit 35V. This allows wireless circuits 35V and 35H to transmit THF signals 32 with corresponding (orthogonal) polarizations, and allows wireless circuits 35V and 35H to receive THF signals 32 with corresponding (orthogonal) polarizations.

[0054] To minimize space within device 10, wireless circuit 35V may be vertically stacked above or below wireless circuit 35H (e.g., where optical mixer 42V partially or completely overlaps with optical mixer 42H). In this example, both wireless circuits 35V and 35H may be formed on the same substrate, such as a semiconductor substrate (e.g., a semiconductor chip, semiconductor bulk, etc.), a rigid printed circuit board, or a flexible printed circuit. Radiator 36 in wireless circuit 35V may be formed, for example, on a different layer of the substrate than radiator 36 in wireless circuit 35H, or radiator 36 in wireless circuit 35V may be formed on the same layer of the substrate as radiator 36 in wireless circuit 35H. Optical mixer 42V may be formed on the same layer of the substrate as optical mixer 42H, or optical mixer 42V may be formed on a different layer of the substrate than optical mixer 42H. Optical mixer 42V can be formed on the same layer of the substrate as radiator 36 in wireless circuit 35V, or it can be formed on a different layer of the substrate than radiator 36 in wireless circuit 35V. Optical mixer 42H can be formed on the same layer of the substrate as radiating element arm 36 in wireless circuit 35H, or it can be formed on a different layer of the substrate than radiator 36 in wireless circuit 35H.

[0055] If needed, Figure 4 The wireless circuit 35 or wireless circuit 35H and 35V can be integrated into the phased antenna array. Figure 5 This diagram illustrates an example of how wireless circuits 35H and 35V can be integrated within a phased antenna array. (See diagram for example.) Figure 5As shown, device 10 may include a phased antenna array 46 of stacked wireless circuits 35H and 35V arranged in a rectangular grid of rows and columns. Each of these antennas in the phased antenna array 46 may be formed on the same substrate. This is illustrative and not limiting. In general, the phased antenna array 46 (sometimes referred to as a phased array antenna) may include any desired number of wireless circuits 35V and 35H (or non-stacked wireless circuits 35) arranged in any desired pattern. Each of these antennas in the phased antenna array 46 may be provided with a corresponding optical phase shift S( Figure 2 and Figure 3 The optical phase shift configures the antenna to co-transmit the combined signal beam to form a THF signal 32 in the desired beam pointing direction and / or receive a THF signal 34 coherently summed at device 10 from the desired beam pointing direction. The beam pointing direction can be selected to direct the signal beam toward external communication equipment, toward a desired external object, away from an external object, etc.

[0056] The phased antenna array 46 can occupy a relatively small space within the device 10. For example, each wireless circuit 35V / 35H can have a length of 48 (e.g., measured from one end of a radiating element arm to the opposite end of the opposite radiating element arm). The length 48 can be approximately equal to half the wavelength of the THF signals 32 and 34. For example, the length 48 can be as small as 0.5 mm or less. Each optical mixer 42 in the phased antenna array 46 can occupy a side area of ​​100 square micrometers or less. Figures 2 to 5 The examples are illustrative and not limiting. In general, each antenna can have any desired antenna radiating element architecture.

[0057] Wireless circuit 24 ( Figure 1 It may include a first light source and a second light source for transmitting wireless data using the corresponding wireless circuit 35. Figure 6 This is a circuit diagram illustrating an example in which the first and second light sources use corresponding wireless circuits 35 to transmit wireless data.

[0058] like Figure 6As shown, wireless circuit 35 may include an optical mixer (PM) 42 and one or more radiators 36 coupled to PM 42. Wireless circuit 24 may include radio frequency transmitter circuitry such as a transmit (TX) chain 64, radio frequency receiver circuitry such as a receive (RX) chain 62, and optical clock circuitry. The optical clock circuitry may include a first optical local oscillator (LO) light source (emitter), such as a laser 60A (e.g., a first laser source, a laser diode, etc.), and may include a second optical LO light source, such as a laser 60B (e.g., a second laser source, a laser diode, etc.). The specific implementation of a laser as the optical LO light source is described herein by way of example. More generally, other types of light sources may be used to generate optical LO signals in wireless circuit 24 (e.g., any desired electromagnetic energy, light, or optical energy).

[0059] Laser 60A, laser 60B, TX chain 64, and RX chain 62 can form transceiver circuit 26. Figure 1 PM 42 is part of the electro-optic transceiver in transceiver circuit 26. The electro-optic transceiver can be coupled to the wireless circuit 35 via signal path 28. PM 42 and / or signal path 28 may form part of the electro-optic transceiver in transceiver circuit 26, or may be separate from transceiver circuit 26.

[0060] Signal path 28 may include an optical signal path. If desired, signal path 28 may also include one or more radio frequency signal paths, such as signal paths 66 and 44. Signal path 44 may be coupled to an electrical output terminal of PM 42. PM 42 may also have a receiver. Figure 2 and Figure 3 control signal V BIAS Electrical input terminals (e.g., Figure 2 and Figure 3 The bias terminal 38 (for clarity, in) Figure 6 (Not shown in the image). As described herein, a radio frequency (RF) signal path may transmit RF signals, including intermediate frequency (IF) signals, and may sometimes be referred to herein as an IF signal path, an electrical signal path, or simply a signal path. An RF signal path may include a coaxial cable, a stripline transmitter, a microstrip transmitter, a coplanar waveguide transmitter, a grounded coplanar waveguide transmitter, and / or any other desired RF transmitter that transmits electrical signals at radio frequency (e.g., intermediate frequency).

[0061] The optical signal path in signal path 28 may include optical path 50 and optical path 52. For example, optical paths 50 and 52 may include optical fibers and / or waveguides. Optical path 50 may optically couple the output of laser 60B to the optical input of PM 42 (e.g., the photosensitive portion of PM 42). Optical path 52 may optically couple the output of laser 60A to the optical input of PM 42 (e.g., the same photosensitive portion of PM 42 coupled to optical path 50 or a different photosensitive portion of PM 42). If desired, an optical combiner (not shown) may optically couple both optical paths 50 and 52 to a single optical input or photosensitive portion of PM 42 (e.g., the optical combiner may use the optical signals carried on optical paths 50 and 52 to illuminate PM 42).

[0062] Laser 60A can output (e.g., generate, produce, emit, etc.) a first optical local oscillator signal LO1 at a first optical frequency F1 to optical path 52. Frequency F1 can be an absolute frequency in the visible, near-infrared, infrared, or ultraviolet spectra. Similarly, laser 60B can output a second optical local oscillator signal LO2 at a second optical frequency F2 to optical path 50. Frequency F2 can be an absolute frequency in the visible, near-infrared, infrared, or ultraviolet spectra.

[0063] Frequency F2 can be offset from frequency FLO1 by a frequency offset equal to the frequency of the THF signal transmitted by wireless circuit 35 (e.g., between 100 GHz and 1 THz, between 100 GHz and 2 THz, between 300 GHz and 800 GHz, between 300 GHz and 1 THz, between 300 GHz and 400 GHz, between 100 GHz and 300 GHz, etc.). The frequency of the THF signal transmitted by wireless circuit 35 is sometimes referred to herein as the beat frequency FB or differential beat frequency FB. Consider an example where frequency F1 is equal to 200,000 GHz and frequency F2 is equal to 200,300 GHz. In this example, the frequency offset is equal to 200,300 GHz - 200,000 GHz = 300 GHz, and optical local oscillator signals LO1 and LO2 can drive optical mixer 42 to transmit THF signals 32 and / or 34 at a beat frequency FB = 300 GHz.

[0064] An electro-optic modulator, such as an electro-optic modulator (EOM) 54, may be disposed on the optical path 50 between the laser 60B and PM 42. The EOM 54 may be, for example, a Mach-Zehnder modulator (MZM) or any other desired type of EOM that uses an electrical signal received from the TX chain 64 to modulate an optical signal. The EOM 54 may include a first optical arm (branch) and a second optical arm (branch) coupled in parallel to the first optical arm on the optical path 50. The EOM 54 may include one or more electrodes extending along either side of the optical arm. An electrical signal applied to the electrodes (e.g., a voltage signal applied across the arm) may control the EOM 54 to modulate information from the electrical signal (e.g., wireless data) onto an optical local oscillator signal LO2 transmitted through the optical path 50. For example, the TX chain 64 may transmit an (electrical) radio frequency (e.g., intermediate frequency) signal carrying wireless data DAT onto the signal path 66. EOM 54 can modulate wireless data DAT onto optical local oscillator signal LO2, thereby generating a modulated optical local oscillator signal LO2' that illuminates PM 42.

[0065] If necessary, an optical phase shifter, such as optical phase shifter 56, can be placed on the optical path 52 between laser 60A and PM 42. Control circuit 14 ( Figure 1 The optical phase shifter 56 can be provided with a phase control signal CTRL1. The phase control signal CTRL1 controls the optical phase shifter 56 to apply an optical phase shift S to the optical local oscillator signal LO1 on the optical path 52. Figure 2 and Figure 3 Phase shift S can be selected to guide the signal beam of THF signal 32 / 34 in the desired pointing direction. Optical phase shifter 56 can phase-shift the optical local oscillator signal LO1 (in... Figure 2 and Figure 3 The signal (represented as LO1+S) is passed to PM 42. Alternatively, EOM 54 may assign a phase shift S to the optical local oscillator signal LO2.

[0066] Signal beamguiding is performed in the optical domain (e.g., using optical phase shifter 56) rather than in the THF domain because there is no satisfactory phase-shifting circuit component that operates at a frequency as high as that of the THF signals 32 and 34. Optical paths 50 and 52 can be used to illuminate PM 42 with corresponding optical local oscillator signals LO2 and LO1 for transmitting or receiving signals below THz. Optical phase shifter 56 can be omitted if desired. Alternatively, EOM 54 can be provided on optical path 52, and / or optical phase shifter 56 can be provided on optical path 50 if desired.

[0067] TX chain 64 may include electrical components for transmitting wireless data DAT in the THF signal 32 transmitted by wireless circuit 35. TX chain 64 may include, for example, data modulation (coding) circuitry such as one or more signal modulators, up-conversion circuitry such as one or more mixers, amplifier circuitry such as one or more power amplifiers (PAs), conversion circuitry such as one or more digital-to-analog converters (DACs), etc. RX chain 62 may include electrical components for receiving wireless data in the THF signal 34 incident on wireless circuit 35. RX chain 62 may include, for example, data demodulation (decoding) circuitry such as one or more signal demodulators, down-conversion circuitry such as one or more mixers, amplifier circuitry such as one or more low-noise amplifiers (LNAs), conversion circuitry such as one or more analog-to-digital converters (ADCs), etc.

[0068] Figure 6 The example is illustrative and non-limiting, wherein PM 42 transmits an electrical signal in the (electrical) radio frequency domain to RX chain 62 via signal path 44. Alternatively, PM 42 may generate an optical signal based on the electrical signal received from radiator 36, and the optical signal may be transmitted to an optical receiver via optical path 50, optical path 52, and / or different optical paths. Signal path 44 and RX chain 62 may be omitted if desired (e.g., Figure 6 The wireless circuit 24 can be a dedicated signal transmitter. Signal path 66 and TX chain 64 can be omitted if needed (e.g., Figure 6 The wireless circuit 24 can be a dedicated signal receiver.

[0069] The high frequencies of THF signals 32 and 34 make wireless circuitry 24 particularly sensitive to phase noise and jitter that can degrade wireless performance. If necessary, wireless circuitry 24 may be equipped with one or more circuit loops for minimizing phase noise and jitter. The circuitry in these loops may include circuitry for accurately and precisely detecting the frequency F1 of optical local oscillator signal LO1 and the frequency F2 of optical local oscillator signal LO2. Wireless circuitry 24 can use the detection of frequencies F1 and F2 to adjust the operation of laser 60A, laser 60B, and / or other parts of wireless circuitry 24 during signal transmission and / or reception in a manner that minimizes phase noise / jitter and optimizes wireless performance. Measuring frequencies F1 and F2 can be very difficult and may consume excessive power if not handled carefully (e.g., requiring a large laboratory optical workbench or other measuring equipment external to device 10). To minimize the circuit complexity and power required for accurate measurement of frequencies F1 and F2 (e.g., to allow wireless circuit 24 to be implemented in compact, lightweight, and / or portable devices such as user equipment (UE) devices), wireless circuit 24 may include an optical resonator, a frequency-locked loop (FLL), and a phase-locked loop (PLL) coupled around lasers 60A and 60B.

[0070] Figure 7 This is a circuit diagram illustrating an example of how wireless circuit 24 can include optical resonators, FLLs, and PLLs coupled around lasers 60A and 60B. Figure 7 In the example, for clarity, the following has been omitted. Figure 6 The radiator 36, TX chain 64, EOM 54, optical phase shifter 56, signal path 66, signal path 44, and RX chain 62. Although described herein as being implemented in wireless circuit 24, Figure 7 The circuit shown can be implemented in any desired electro-optic component of device 10 (e.g., where an optical signal is used to generate an electrical signal, or vice versa).

[0071] like Figure 7 As shown, wireless circuit 24 may include loop circuitry coupled around lasers 60A and 60B. The loop circuitry may include an FLL circuit such as FLL 74, and may include a PLL circuit such as PLL 78. It may also include an electrical counter such as electrical counter 70, and one or more optical resonators 84, such as at least a first optical resonator 84-1 and a second optical resonator 84-2. For clarity, PLL 78, FLL 74, and electrical counter 70 are... Figure 7 The PLL 74 is shown as a separate block. In practice, the FLL 74 may itself form an electrical counter 70 (e.g., the electrical counter 70 may be implemented using an FLL 78), and / or the PLL 78 may include the FLL 74 (e.g., the FLL 74 may be implemented within the PLL 78, and the PLL 78 may perform phase alignment between the input signals). The PM 42 may have an electrical output terminal coupled to a signal path 76 (e.g., an electrical radio frequency signal path). The input of the FLL 74 may be coupled to the signal path 76. The input of the PLL 78 may be coupled to the signal path 76. The electrical counter 70 may be disposed on the signal path 76. Alternatively, the electrical counter 70 may be included within the FLL 74 and / or the PLL 78 as part of a crystal oscillator circuitry within and / or coupled to the FLL and / or the PLL, and / or may be disposed at an electrical output of the PM 42.

[0072] FLL 74 can be coupled to optical resonator 84-1 via signal path 80. PLL 78 can be coupled to optical resonator 84-2 via signal path 82. Optical resonator 84-1 can be physically located at a first position along the length of optical path 50 (e.g., within the optical coupling distance of optical path 50). Optical resonator 84-1 can be optically coupled to optical path 50 and electrically coupled to signal path 80. Optical resonator 84-2 can be physically located at a second position along the length of optical path 52 (e.g., within the optical coupling distance of optical path 52). Optical resonator 84-2 can be optically coupled to optical path 52 and electrically coupled to signal path 82.

[0073] Optical path 50, PM 42, signal path 76, FLL 74, signal path 80, and optical resonator 84-1 can form a first loop path 71 (e.g., FLL and / or injection-locked loop path) around laser 60B. Optical path 52, PM 42, signal path 76, PLL 78, signal path 82, and optical resonator 84-2 can form a second loop path 73 (e.g., PLL and / or injection-locked loop path) around laser 60A. Optical resonator 84 can be, for example, an optical microresonator (MR), each containing an optical loop (e.g., a loop of an optical fiber or waveguide). The loops of the optical resonators can carry optical signals in a set of optical resonances, each optical resonance at a corresponding optical resonant frequency. This set of optical resonances is sometimes referred to herein as an optical comb or frequency comb.

[0074] Given the dimensions of optical resonator 84 (e.g., the diameter D1 of optical resonator 84-1 or the diameter D2 of optical resonator 84-2), a specific optical resonance can be established in the optical comb of the optical resonator. An incident optical signal on the optical resonator (e.g., along optical path 50 of optical resonator 84-1 or along optical path 52 of optical resonator 84-2) can be reflected in opposite directions along optical path 52 at the frequency of the optical comb of the optical resonator. The reflected optical signal can be injected into the laser 60 that emitted the optical signal (e.g., to create an injection-locked laser).

[0075] For example, Figure 7 Section 72 plots the optical resonance (through-path emission as a function of frequency) of optical resonator 84-1 when configured to exhibit the nominal diameter D1. Figure 7 As shown by curve 81 in section 72, when the optical resonator 84-1 has a nominal diameter D1, the optical resonator 84-1 can exhibit a set or comb-like optical resonance (indicated by the minimum value of curve 81). Each optical resonance is separated in frequency space by a corresponding free spectral range (FSR), denoted as FSR1. If needed, a control signal CTRL5 can be provided to the optical resonator 84-1 (e.g., via...). Figure 1The control circuit 14) can be used to increase or decrease the diameter D1 away from the nominal diameter D1 (e.g., using a piezoelectric actuator or another electromechanical actuator based on an electrical signal such as control signal CTRL5 to adjust the physical dimensions of the optical resonator 84-1, using a thermal circuit, using a PN junction, etc.). This can be used to offset or tune the frequency of the optical resonance of the optical resonator 84-1 and / or adjust or tune the free spectral range FSR1 of the optical resonator 84-1. The free spectral range FSR1 is sometimes referred to herein as frequency spacing FSR1, frequency divider FSR1, comb spacing / divider FSR1, optical resonator spacing / divider FSR1, or simply frequency FSR1.

[0076] Similarly, Figure 7 Section 86 plots the optical resonance (through-path emission as a function of frequency) of optical resonator 84-2 when configured to exhibit the nominal diameter D2. (See diagram 86.) Figure 7 As shown by curve 83 in section 86, when the optical resonator 84-2 has a nominal diameter D2, the optical resonator 84-2 can exhibit a set or comb-like optical resonance (indicated by the minimum value of curve 83). Each optical resonance is separated in frequency by a corresponding free spectral range denoted as FSR2. If needed, a control signal CTRL4 can be provided to the optical resonator 84-2 (e.g., via...). Figure 1 The control circuit 14) can be used to increase or decrease the diameter D2 away from the nominal D2 (e.g., by using a piezoelectric actuator or another electromechanical actuator based on an electrical signal such as the control signal CTRL4 to adjust the physical dimensions of the optical resonator 84-2, by using a thermal circuit, by using a PN junction, etc.). This can be used to offset or tune the frequency of the optical resonance of the optical resonator 84-2 and / or adjust or tune the free spectral range FSR2 of the optical resonator 84-2. The free spectral range FSR2 is sometimes referred to herein as frequency spacing FSR2, frequency divider FSR2, comb spacing / divider FSR2, optical resonator spacing / divider FSR2, or simply frequency FSR2.

[0077] During operation (e.g., wireless signal transmission or reception), laser 60B can output an optical local oscillator signal LO2 to optical path 50 at frequency F2. If needed, laser 60B can receive control signal CTRL3 (e.g., by...). Figure 1 The control circuit 14 provides a laser bias voltage, which controls the laser 60B to tune the frequency F2 of the optical local oscillator signal LO2. Simultaneously, the laser 60A can output the optical local oscillator signal LO1 to the optical path 52 at frequency F1. If needed, the laser 60A can receive a control signal CTRL2 (e.g., from...). Figure 1The control circuit 14 provides the laser bias voltage, and the control signal controls the frequency F1 of the laser 60A tuning optical local oscillator signal LO1.

[0078] Optical path 50 transmits the optical local oscillator signal LO2 to PM 42. At least some of the optical local oscillator signals LO2 can be optically coupled away from optical path 50 and coupled to optical resonator 84-1. The portion of the optical local oscillator signals LO2 coupled away from optical path 50 can resonate within optical resonator 84-1 (e.g., around an optical loop in optical resonator 84-1 at a frequency given by a corresponding optical resonant comb having a free spectral range FSR1). Simultaneously, optical path 52 transmits the optical local oscillator signal LO1 to PM 42. At least some of the optical local oscillator signals LO1 can be optically coupled away from optical path 52 and coupled to optical resonator 84-2. The portion of the optical local oscillator signals LO1 coupled away from optical path 52 can resonate within optical resonator 84-2 (e.g., around an optical loop in optical resonator 84-2 at a frequency given by a corresponding optical resonant comb having a free spectral range FSR2).

[0079] PM 42 can generate an electrical signal BSIG based on the optical local oscillator signal LO2 on optical path 50 and the optical local oscillator signal LO1 on optical path 52 (e.g., in a heterodyne process) at a beat frequency FB. The beat frequency FB is equal to the difference between frequencies F2 and F1. The electrical signal BSIG can be a beat frequency signal, and is sometimes referred to herein as the beat frequency signal BSIG or the difference beat signal BSIG. PM 42 can output the electrical signal BSIG to signal path 76, and optionally output to... Figure 6 On the radiator 36.

[0080] The electrical counter 70 can generate frequency information FINFO based on the electrical signal BSIG (e.g., as an analog or digital signal). The electrical counter 70 (sometimes referred to herein as an electrical frequency detector 70 or frequency counter 70) can, for example, identify (e.g., detect, measure, output, calculate, determine, etc.) the beat frequency FB of the beat frequency signal BSIG (e.g., using a frequency counter that uses the same system clock signal used to time FLL 74 and / or PLL 78). The frequency information FINIFO may include or otherwise identify the beat frequency FB detected using the electrical counter 70. The electrical counter 70 can send data to control circuit 14 (…). Figure 1 FINFO provides frequency information for further processing.

[0081] FLL 74 may include a counter, filter circuitry, and / or other FLL circuitry involved in performing FLL around laser 60B. FLL 74 may generate an FLL control signal FLLCTRL based on the electrical signal BSIG. FLL 74 may provide the FLL control signal FLLCTRL to optical resonator 84-1, which injects and locks laser 60B into optical resonator 84-1. Optical resonator 84-1 may reflect at least some of the optical local oscillator signal LO2 emitted by laser 60B onto optical path 50 back to laser 60B (as indicated by arrow 67), which is used to inject laser 60B into one of the optical resonators in the optical comb of optical resonator 84-1.

[0082] PLL 78 may include a frequency divider, a phase detector, an undersampled mixer, a loop filter, and / or other PLL circuitry involved in performing the PLL around laser 60A. PLL 78 may generate a PLL control signal PLLCTRL based on the electrical signal BSIG. PLL 74 may provide the PLL control signal PLLCTRL to optical resonator 84-2, which injects and locks laser 60A into optical resonator 84-2. Optical resonator 84-2 may reflect at least some of the optical local oscillator signal LO1 emitted by laser 60A onto optical path 50 back to laser 60A (as indicated by arrow 65), which is used to inject laser 60A into one of the optical resonators in the optical comb of optical resonator 84-2.

[0083] Injecting and locking laser 60B into optical resonator 84-1 and laser 60A into optical resonator 84-2 in this manner can reduce phase noise and jitter of lasers 60A and 60B over a wide range of frequencies below THz of the electrical signal BSIG. Further frequency control can be performed by tuning the optical resonances of optical resonators 84-1 and 84-2 (e.g., using control signals CTRL5 and CTRL4, respectively), where lasers 60A and 60B follow the frequency variations caused by injection locking.

[0084] Figure 7 The example is illustrative and non-limiting. FLL 74 and signal path 80 may be omitted if necessary. In this example, PLL 78 may receive the beat frequency signal BSIG at beat frequency FB from PM 42 and from a system clock such as a crystal oscillator (XO) or a bulk acoustic wave (BAW) reference oscillator (for clarity, ...). Figure 7(Not shown) receives a clock signal. In these specific implementations, laser 60B is injected and locked to optical resonator 84-1, and laser 60A is injected and locked to optical resonator 84-2 (e.g., to reduce the phase noise of the laser). Further phase noise reduction can be performed within PLL 78, and frequency control can be performed by locking one of the optical resonators to the system clock via PLL 78.

[0085] Figure 8 Exemplary optical combs for optical resonators 84-1 and 84-2 are shown. Figure 8 The line (peak) 92 plots the optical resonance of the optical comb of optical resonator 84-1. Figure 8 Line 94 plots the optical resonance of the optical comb of optical resonator 84-2. As shown in line 92, optical resonator 84-1 may have a first free spectral range FSR1. As shown in line 94, optical resonator 84-2 may have a second free spectral range FSR2 that is different from (e.g., narrower than) the free spectral range FSR1. This can be used to offset line 94 from each of lines 92 within the corresponding frequency range 96 (e.g., from frequency FA to frequency FB). Lasers 60A and 60B may have a hardware tuning range 90 (e.g., from frequency FC to frequency FD). Lasers 60A and 60B may exhibit greater stability near the center of the tuning range 90 than near the edges of the tuning range 90.

[0086] After lasers 60A and 60B are initially powered on, laser 60B can be locked to any one of the optical resonances within the tuning range of optical resonator 84-1 in the optical comb of optical resonator 84-1 (e.g., locked to any one of the lines 92 overlapping the tuning range 90). The bias conditions of laser 60B (e.g., as used with...) Figure 7 The control signal CTRL3 (set by the laser) can be used to set which optical resonance (line 92) of optical resonator 84-1 laser 60B is locked to. Similarly, laser 60A can be locked to any optical resonance in the optical comb of optical resonator 84-2 within the tuning range of laser 60A (e.g., locked to any line of line 94 overlapping the tuning range 90). The bias conditions of laser 60A (e.g., as used with...) Figure 7 The control signal CTRL2 can be used to set which optical resonator (line 94) the laser 60A is locked to.

[0087] Once lasers 60A and 60B are locked, control circuit 14 ( Figure 1 The beat frequency FB and the free spectral ranges FSR1 and FSR2 can be accurately measured using the instrument and the counter 70. The counter 70 can directly measure the beat frequency FB of the electrical signal BSIG output from the PM 42.

[0088] Control circuit 14 can measure the amplitude of the free spectral range FSR1 by: setting the bias of laser 60B to generate an optical local oscillator signal LO2 (e.g., line 92-1) at a first optical resonant frequency in the optical comb of optical resonator 84-1; measuring the resulting beat frequency FB of electrical signal BSIG using counter 70; changing the bias of laser 60B to generate an optical local oscillator signal LO2 (e.g., line 92-2) at the next adjacent optical resonant frequency in the optical comb of optical resonator 84-1, while keeping the bias of laser 60A and the frequency of optical local oscillator signal LO1 constant; and measuring the resulting beat frequency FB of electrical signal BSIG using counter 70. Control circuit 14 can identify (e.g., calculate, derive, estimate, infer, extrapolate, determine, detect, etc.) the free spectral range FSR1 based on the change in beat frequency FB between two bias settings of laser 60B.

[0089] Similarly, control circuit 14 can measure the amplitude of the free spectral range FSR2 by: setting the bias of laser 60A to generate an optical local oscillator signal LO2 (e.g., line 94-1) at a first optical resonant frequency in the optical comb of optical resonator 84-2; measuring the resulting beat frequency FB of electrical signal BSIG using counter 70; changing the bias of laser 60A to generate an optical local oscillator signal LO1 (e.g., line 94-2) at the next adjacent optical resonant frequency in the optical comb of optical resonator 84-2, while keeping the bias of laser 60B and the frequency of optical local oscillator signal LO2 constant; and measuring the resulting beat frequency FB of electrical signal BSIG using counter 70. Control circuit 14 can identify (e.g., calculate, derive, estimate, infer, extrapolate, determine, detect, etc.) the free spectral range FSR2 based on the change in beat frequency FB between two bias settings of laser 60A.

[0090] Once the control circuit 14 has detected the bias frequency FB, the free spectral range FSR1, and the free spectral range FSR2, the control circuit 14 can clearly identify (e.g., calculate, derive, estimate, infer, extrapolate, determine, detect, etc.) the absolute frequency F2 of the laser 60B and the optical local oscillator signal LO2, and the absolute frequency F1 of the laser 60A and the optical local oscillator signal LO1. Figure 9 It can be made by wireless circuit 24 ( Figure 6 and Figure 7 The flowchart shows the exemplary operation performed by the control circuit 14 to clearly measure the frequencies F1 and F2 used for wireless communication.

[0091] In operation 100, control circuit 14 can energize lasers 60A and 60B. Laser 60B can begin outputting the optical local oscillator signal LO2 to optical path 50. Laser 60A can begin outputting the optical local oscillator signal LO1 to optical path 52.

[0092] In operation 102, FLL 74 can use the optical local oscillator signal LO2 (e.g., at the corresponding optical resonant frequency in the optical comb of optical resonator 84-1) to inject and lock the laser 60B to optical resonator 84-1.

[0093] In operation 104, PLL 78 can use the optical local oscillator signal LO1 (e.g., at the corresponding optical resonant frequency in the optical comb of optical resonator 84-2) to inject and lock the laser 60A to optical resonator 84-2.

[0094] In operation 106, control circuit 14 can adjust laser 60B, optical resonator 84-1, laser 60A, and / or optical resonator 84-2 to meet the laser frequency ambiguity resolution conditions. For example, control circuit 14 can use control signal CTRL3 to adjust laser 60B, control signal CTRL2 to adjust laser 60A, control signal CTRL5 to adjust optical resonator 84-1, and control signal CTRL4 to adjust optical resonator 84-2.

[0095] The ambiguity resolution condition can be a condition that allows the control circuit 14 to explicitly identify the absolute frequency F2 of the optical local oscillator signal LO2 and the absolute frequency F1 of the optical local oscillator signal LO1 based on the measurement of the difference frequency FB of the difference frequency signal BSIG and the measurement of the free spectral ranges FSR1 and FSR2. For example, the ambiguity resolution condition can be satisfied by controlling the optical resonator 84-1 to tune the free spectral range FSR1 and by controlling the optical resonator 84-2 to tune the free spectral range FSR2, such that the greatest common divisor (GCD) of the free spectral ranges FSR1 and FSR2 (e.g., when FSR1 and FSR2 are rounded to an integer multiple of the frequency increment such as 1 mHz, 1 Hz, 1 MHz, etc.) is less than or equal to a predetermined integer (upper limit) threshold or limit (e.g., rounded to an integer multiple of the frequency increment such as 1 mHz, 1 Hz, 1 MHz, etc.). As an example, the predetermined threshold or limit may be between 10MHz and 15MHz, between 5MHz and 15MHz, between 5MHz and 10MHz, between 1MHz and 10MHz, between 1MHz and 15MHz, between 0.5MHz and 5MHz, between 0.5MHz and 2MHz, or approximately 1MHz. To satisfy this condition, the free spectral range FSR1 may differ from the free spectral range FSR2 (e.g., the comb spacing of optical resonator 84-1 differs from the comb spacing of optical resonator 84-2). When the condition is met, the control circuit 14 can explicitly calculate the absolute frequencies F1 and F2 based on the free spectral ranges FSR1 and FSR2 and the beat frequency FB.

[0096] Once laser 60B, optical resonator 84-1, laser 60A, and optical resonator 84-2 have been adjusted to meet the laser frequency ambiguity resolution conditions, the electronic counter 70 can measure the beat frequency FB, the control circuit 14 and the electronic counter 70 can measure the free spectral range FSR1 of optical resonator 84-1, and the control circuit 14 and the electronic counter 70 can measure the free spectral range FSR2 of optical resonator 84-2 (in operation 108).

[0097] In operation 110, control circuit 14 can explicitly identify (e.g., detect, calculate, output, estimate, determine, extrapolate, etc.) the absolute frequency F1 of optical local oscillator signal LO1 and the absolute frequency F2 of optical local oscillator signal LO2 based on measurements of beat frequency FB, free spectral range FSR1, and free spectral range FSR2 performed in operation 108. Since the adjustment in operation 106 satisfies the ambiguity resolution conditions, the measurements of frequencies F1 and F2 can be explicit.

[0098] Consider an example where optical resonator 84-1 is adjusted (in operation 106) to exhibit a free spectral range FSR1 = 200,003 MHz and optical resonator 84-2 is adjusted to exhibit a free spectral range FSR2 = 75,011 MHz. In this example, when the predetermined limit of the integer GCD is approximately 1 MHz (e.g., when the frequency is rounded to an integer multiple of an increment such as 1 mHz, 1 Hz, 1 MHz, etc.), the ambiguity resolution condition is met, and different measurements of the beat frequency FB can correspond to different explicit values ​​of frequencies F1 and F2. As a first example, when the measured beat frequency FB is equal to 300768 MHz (corresponding to a multiplier of 2609 and 977), the control circuit 14 can accurately and explicitly determine that frequency F1 is equal to 195703699 MHz and frequency F2 is equal to 195402931 MHz. As a second example, when the measured beat frequency FB equals 300847MHz (corresponding to the multiplier of 2617 and 980), the control circuit 14 can accurately and definitively determine that frequency F1 equals 196303787MHz and frequency F2 equals 196002940MHz. As a third example, when the measured beat frequency FB equals 300926MHz (corresponding to the multiplier of 2625 and 983), the control circuit 14 can detect that frequency F1 equals 196903875MHz and frequency F2 equals 196602949MHz. As a fourth example, when the measured beat frequency FB equals 301005MHz (corresponding to the multiplier of 2633 and 986), the control circuit 14 can detect that frequency F1 equals 197503963MHz and frequency F2 equals 197202958MHz. As a fifth example, when the measured beat frequency FB equals 301084MHz (corresponding to the multiplier of 2641 and 989), the control circuit 14 can detect that frequency F1 equals 198104051MHz and frequency F2 equals 197802967MHz. As a sixth example, when the measured beat frequency FB equals 301163MHz (corresponding to the multiplier of 2649 and 992), the control circuit 14 can detect that frequency F1 equals 198704139MHz and frequency F2 equals 198402976MHz. As a seventh example, when the measured beat frequency FB equals 301242MHz (corresponding to the multiplier of 2657 and 995), the control circuit 14 can detect that frequency F1 equals 199304227MHz and frequency F2 equals 199002985MHz.

[0099] If the integer GCD of the free spectral ranges FSR1 and FSR2 is too large (e.g., greater than about 10 MHz to 15 MHz), the absolute frequencies F1 and F2 may not be calculated uniquely. For example, if the free spectral range FSR1 = 75,000 and the free spectral range FSR2 = 200,000, the integer GCD is 25,000 MHz instead of 1 MHz. At these frequencies, 8 * FSR1 = 3 * FSR2 = 600 GHz. If the tuning range of the laser is several times 600 GHz, 600 GHz can be added to one laser and subtracted from another laser to obtain the same beat frequency FB output by the PM 42.

[0100] The ambiguity resolution condition for the maximum integer GCD values ​​of the free spectral ranges FSR1 and FSR2 can be readily satisfied. This is because the probability that two random integers are coprime (i.e., the integer GCD is 1) is approximately 61%. The probability that the integer GCDs of any two frequencies (e.g., accurate to approximately 1 Hz or the closest integer multiple rounded to 1 Hz) are greater than 10 MHz is approximately 10%. -7 Therefore, arbitrary frequencies of the free spectral ranges FSR1 and FSR2 can be used and measured, the integer GCD of the free spectral range can be calculated (e.g., using the Euclidean algorithm), and in cases where the integer GCD is unlikely to be too large, one of the free spectral ranges can be slightly modified to obtain a sufficiently low integer GCD (e.g., below the upper limit defined by the ambiguity resolution condition).

[0101] The uniqueness of the multiplier may require knowing the sign of the beat frequency (FB). Since there is no phase, the sign cannot be measured directly. However, the multiplier for either the free spectral range FSR1 or FSR2 can be changed to examine how the frequency changes, and that multiplier can then be used to determine the sign. For simplicity, these examples describe integers. In reality, frequencies are real numbers. FSR and beat frequencies can be measured to values ​​better than 1 Hz, so integers are used as reasonable approximations. In this way, Figure 7 The wireless circuit 24 can form a spatially and power-efficient optical frequency counter for optical local oscillator signals.

[0102] In operation 112, wireless circuit 24 can perform wireless communication (e.g., using...) Figure 6The wireless circuit 24 can transmit and / or receive wireless data (using THF signals 32 and / or 34) and / or adjust wireless communication based on the frequency F1 identified by the optical local oscillator LO1 and the frequency F2 identified by the optical local oscillator LO2 (e.g., by adjusting antenna tuning, the transmitted THF signal, the frequency of laser 60A and / or laser 60B, etc.). For example, the wireless circuit 24 can be scheduled to transmit THF signal 32 at a given sub-THz frequency Z. The frequencies F1 and F2 can be explicitly measured (e.g., using operations 100 to 110). It can be determined whether the difference between frequencies F1 and F2 is sufficiently close to the sub-THz frequency Z. If the difference between frequencies F1 and F2 is too far from the sub-THz frequency Z, laser 60A and / or laser 60B can be adjusted to adjust frequencies F1 and / or F2 until the difference between frequencies F1 and F2 is sufficiently close to the sub-THz frequency Z. If needed, once lasers 60A and 60B have been locked and their absolute frequencies F1 and F2 have been explicitly measured in this manner, control circuit 14 can measure any third laser (see example) by beating one of lasers 60A and 60B with laser 60C (e.g., at PM 42) and measuring the resulting beating frequency FB. Figure 7 The absolute frequency of the laser (60C). For example, Figure 9 Wireless communication is described herein. The wireless communication described herein can be replaced by wired communication (e.g., an antenna element can be replaced by a wireless link to an external device or circuit). In operation 112, wired communication may be performed instead of wireless communication. Wireless circuit 24 is sometimes more generally referred to herein as circuit 24 or communication circuit 24.

[0103] As used herein, the term "simultaneous" means at least partially overlapping in time. In other words, the first and second events are referred to herein as "simultaneous" if at least some of the first events occur simultaneously with at least some of the second events (e.g., if at least some of the first events occur during, concurrently with, or when at least some of the second events occur). The first and second events can be simultaneous if they are synchronized (e.g., if the entire duration of the first event overlaps with the entire duration of the second event in time), but they can also be simultaneous if they are not synchronized (e.g., if the first event begins before or after the second event, ends before or after the second event, or if they do not partially overlap in time). As used herein, the term "while" is synonymous with "concurrent."

[0104] Device 10 may collect and / or use personally identifiable information. It is well known that the use of personally identifiable information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to the user.

[0105] According to one embodiment, the communication circuit includes a first laser, an optical mixer, a first optical path coupling the first laser to the optical mixer, a first optical resonator optically coupled to the first optical path, and a phase-locked loop (PLL) coupling the electrical output of the optical mixer to the first optical resonator, wherein the first laser is configured to output a first optical signal to the first optical path.

[0106] According to another embodiment, the first optical resonator may optionally include an optical loop.

[0107] According to another embodiment, the first optical resonator may optionally be configured to receive a control signal that changes the resonant frequency of the optical loop.

[0108] According to another embodiment, the first optical resonator may optionally be configured to inject and lock the first laser into the first optical path.

[0109] According to another embodiment, the communication circuit may optionally include a second laser and a second optical path coupling the second laser to the optical mixer, wherein the first optical signal is at a first frequency, the second laser is configured to output a second optical signal to the second optical path at a second frequency, and the optical mixer is configured to generate an electrical signal at a third frequency equal to the difference between the first and second frequencies.

[0110] According to another embodiment, the communication circuit may also optionally include a second optical resonator optically coupled to the second optical path.

[0111] According to another embodiment, the communication circuit may also optionally include a frequency-locked loop (FLL) that couples the electrical output of the optical mixer to the second optical resonator.

[0112] According to another embodiment, the first optical resonator may optionally exhibit a first optical resonant comb having a first comb spacing, and the second optical resonator may optionally exhibit a second optical resonant comb having a second comb spacing different from the first comb spacing.

[0113] According to another embodiment, the communication circuit may optionally include: a signal path that couples the electrical output of the optical mixer to the input of the FLL and the input of the PLL, the optical mixer being configured to output a beat frequency signal on the signal path based on a first optical signal and a second optical signal; and a processing circuit that is configured to estimate a first frequency and a second frequency based on the frequency of the beat frequency signal, a first FSR, and a second FSR.

[0114] According to another implementation, the first FSR and the second FSR may optionally have a greatest common divisor (GCD) of less than or equal to 15 MHz when rounded to the nearest integer multiple of 1 MHz.

[0115] According to another implementation, the integer GCD may optionally be less than or equal to 2MHz.

[0116] According to another embodiment, the optical mixer may optionally include a single-row carrier photodiode (UTC PD), and the optical resonator may optionally include an optical microresonator. The communication circuit may also optionally include an antenna element coupled to the UTC PD.

[0117] According to one embodiment, an electronic device includes a first laser, an optical mixer, a first optical path coupling the first laser to the optical mixer, a first optical resonator optically coupled to the first optical path, and a frequency-locked loop (FLL) coupling the electrical output of the optical mixer to the first optical resonator, wherein the first laser is configured to output a first optical signal to the first optical path.

[0118] According to another embodiment, the first optical resonator may optionally include an optical loop and be configured to receive a control signal that changes the comb spacing of the first optical resonator.

[0119] According to another embodiment, the first optical resonator may optionally be configured to inject and lock the first laser into the first optical path.

[0120] According to another embodiment, the electronic device may optionally include: a second laser; a second optical path coupled to the second laser to the optical mixer, wherein the first optical signal is at a first frequency, the second laser is configured to output a second optical signal to the second optical path at a second frequency, and the optical mixer is configured to generate an electrical signal at a third frequency equal to the difference between the first frequency and the second frequency; and a second optical resonator optically coupled to the second optical path.

[0121] According to another embodiment, the first optical resonator may optionally exhibit an optical resonant comb with a first comb pitch, and the second optical resonator exhibits an optical resonant comb with a second comb pitch different from the first comb pitch, the first comb pitch and the second comb pitch having a greatest common divisor (GCD) of less than or equal to 10 MHz when rounded to the nearest integer multiple of 1 Hz.

[0122] According to another embodiment, the electronic device may optionally further include: an antenna element coupled to the optical mixer; a signal path coupling the electrical output of the optical mixer to the input of the FLL, the optical mixer being configured to output a beat frequency signal on the signal path based on the first optical signal and the second optical signal; and processing circuitry configured to estimate a first frequency and a second frequency based on the frequency of the beat frequency signal, a first FSR, and a second FSR.

[0123] According to one embodiment, a method for operating a wireless circuit is provided, the method comprising: transmitting a first optical signal at a first frequency to an optical mixer via a first optical path using a first laser; transmitting a second optical signal at a second frequency to the optical mixer via a second optical path using a second laser; generating an electrical signal based on the first optical signal and the second optical signal using the optical mixer; injecting and locking the first laser using a first optical resonator optically coupled to the first optical path based on the electrical signal, wherein the first optical resonator exhibits a first optical resonant comb having a first comb spacing; injecting and locking the second laser using a second optical resonator optically coupled to the second optical path based on the electrical signal, wherein the second optical resonator exhibits a second optical resonant comb having a second comb spacing different from the first comb spacing; and estimating the first frequency and the second frequency using a processing circuit based on the frequency of the electrical signal, the first comb spacing, and the second comb spacing.

[0124] According to another embodiment, the method may also optionally include: using the processing circuit to detect the first comb spacing based on a first change in the electrical signal generated by the bias adjustment of the first laser; and using the processing circuit to detect the second comb spacing based on a second change in the electrical signal generated by the bias adjustment of the second laser.

[0125] The foregoing is merely illustrative and various modifications can be made to the described implementation. The foregoing implementation can be implemented individually or in any combination.

Claims

1. A communication circuit, the communication circuit comprising: First laser; Optical mixer; A first optical path couples the first laser to the optical mixer, and the first laser is configured to output a first optical signal onto the first optical path; A first optical resonator, which is optically coupled to the first optical path; and A phase-locked loop (PLL) couples the electrical output of the optical mixer to the first optical resonator.

2. The communication circuit according to claim 1, wherein the first optical resonator comprises an optical loop.

3. The communication circuit according to claim 2, wherein the first optical resonator is configured to receive a control signal that changes the resonant frequency of the optical loop.

4. The communication circuit of claim 3, wherein the first optical resonator is configured to inject and lock the first laser onto the first optical path.

5. The communication circuit according to claim 1, further comprising: Second laser; and A second optical path couples the second laser to the optical mixer, wherein the first optical signal is at a first frequency, the second laser is configured to output a second optical signal to the second optical path at a second frequency, and the optical mixer is configured to generate an electrical signal at a third frequency equal to the difference between the first frequency and the second frequency.

6. The communication circuit according to claim 5, further comprising: The second optical resonator is optically coupled to the second optical path.

7. The communication circuit according to claim 6, further comprising: A frequency-locked loop (FLL) couples the electrical output of the optical mixer to the second optical resonator.

8. The communication circuit of claim 6, wherein the first optical resonator exhibits a first optical resonant comb having a first comb spacing, and the second optical resonator exhibits a second optical resonant comb having a second comb spacing different from the first comb spacing.

9. The communication circuit according to claim 8, further comprising: A signal path that couples the electrical output of the optical mixer to the input of the FLL and the input of the PLL, the optical mixer being configured to output a beat frequency signal on the signal path based on the first optical signal and the second optical signal; and The processing circuit is configured to estimate the first frequency and the second frequency based on the frequency of the beat frequency signal, the first FSR and the second FSR.

10. The communication circuit of claim 8, wherein the first FSR and the second FSR have a greatest common divisor (GCD) of less than or equal to 15 MHz when rounded to the nearest integer multiple of 1 MHz.

11. The communication circuit according to claim 10, wherein the integer GCD is less than or equal to 2MHz.

12. The communication circuit of claim 1, wherein the optical mixer comprises a single-row carrier photodiode (UTC PD), and the optical resonator comprises an optical microresonator, and the communication circuit further comprises an antenna element coupled to the UTCPD.

13. An electronic device, the electronic device comprising: First laser; Optical mixer; A first optical path couples the first laser to the optical mixer, and the first laser is configured to output a first optical signal onto the first optical path; A first optical resonator, which is optically coupled to the first optical path; and A frequency-locked loop (FLL) couples the electrical output of the optical mixer to the first optical resonator.

14. The electronic device of claim 13, wherein the first optical resonator includes an optical loop and is configured to receive a control signal that changes the comb spacing of the first optical resonator.

15. The electronic device of claim 13, wherein the first optical resonator is configured to inject and lock the first laser onto the first optical path.

16. The electronic device according to claim 13, further comprising: Second laser; A second optical path couples the second laser to the optical mixer, wherein the first optical signal is at a first frequency, the second laser is configured to output a second optical signal to the second optical path at a second frequency, and the optical mixer is configured to generate an electrical signal at a third frequency, the third frequency being equal to the difference between the first frequency and the second frequency. and The second optical resonator is optically coupled to the second optical path.

17. The electronic device of claim 16, wherein the first optical resonator exhibits an optical resonant comb with a first comb pitch, and the second optical resonator exhibits an optical resonant comb with a second comb pitch different from the first comb pitch, the first comb pitch and the second comb pitch having a greatest common divisor (GCD) of less than or equal to 10 MHz when rounded to the nearest integer multiple of 1 Hz.

18. The electronic device of claim 17, further comprising: An antenna element coupled to the optical mixer; A signal path that couples the electrical output of the optical mixer to the input of the FLL, the optical mixer being configured to output a beat frequency signal on the signal path based on the first optical signal and the second optical signal; and The processing circuit is configured to estimate the first frequency and the second frequency based on the frequency of the beat frequency signal, the first FSR and the second FSR.

19. A method of operating a wireless circuit, the method comprising: The first laser is used to transmit a first optical signal at a first frequency to the optical mixer through the first optical path; A second laser is used to transmit a second optical signal at a second frequency to the optical mixer through a second optical path; The optical mixer is used to generate an electrical signal based on the first optical signal and the second optical signal; The first laser is locked based on the electrical signal injection using a first optical resonator optically coupled to the first optical path, wherein the first optical resonator exhibits a first optical resonant comb with a first comb spacing. The second laser is locked based on the electrical signal injection using a second optical resonator optically coupled to the second optical path, wherein the second optical resonator exhibits a second optical resonant comb with a second comb spacing different from the first comb spacing; as well as The processing circuitry estimates the first frequency and the second frequency based on the frequency of the electrical signal, the first comb spacing, and the second comb spacing.

20. The method according to claim 19, further comprising: The processing circuitry is used to detect the first comb spacing based on a first change in the electrical signal generated by the bias adjustment of the first laser. as well as The processing circuit uses the second change in the electrical signal generated by the bias adjustment of the second laser to detect the second comb spacing.

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