A photonic synthesizer includes a multifrequency optical source to produce a signal of interest from a pair of lasers, which may be self-injection locked chip lasers. The signal is referenced to a high frequency clock using a photonic mixer/divider based on an electro-optical modulator and a relatively slow photodiode. The electro-optical modulator produces optical harmonics from the beams from the pair of lasers, where one harmonic from the first laser beam and one harmonic from the second laser beam beat on the photodiode. A phase locked control signal is generated for controlling the output frequency of one or both of the two lasers. The output signal of the photonic synthesizer is generated using a relatively fast photodiode based on a difference in frequencies of the pair of lasers. The output signal may be a millimeter wave-band signal. The photonic synthesizer can be formed as a photonic integrated circuit (PIC).

Power distribution modules are configured to distribute power to a power-consuming component(s), such as a remote antenna unit(s) (RAU(s)). By “hot” connection and/or disconnection, the power distribution modules can be connected and/or disconnected from a power unit and/or a power-consuming component(s) while power is being provided to the power distribution modules. Power is not required to be disabled in the power unit before connection and/or disconnection of power distribution modules. The power distribution modules may be configured to protect against or reduce electrical arcing or electrical contact erosion that may otherwise result from “hot” connection and/or connection of the power distribution modules.

A MIMO system comprises a remote radio unit (RRU) and central unit. The RRU comprises: a binary phase shift keying (BPSK) modulator, configured to modulate a BPSK waveform by a local oscillator (LO) signal to generate a stimulus signal, wherein the LO signal is derived from a downlink optical signal received via downlink radio over fiber (DL-ROF) from a central unit (CU); and an optical signal generator, in particular a laser, configured to generate an uplink optical signal based on the stimulus signal for transmission via uplink radio over fiber (UL-ROF) to the CU.

A passive optical network includes a central office providing subscriber signals; a drop terminal; and a wave division multiplexer. A fiber distribution hub may split or separate out dedicated optical signals from subscriber optical signals between the central office and the drop terminal. The wave division multiplexer separates dedicated optical signals pertaining to a specific dedicated subscriber from other optical signals on the line received at the wave division multiplexer. The wave division multiplexer may be part of a cable or part of an intermediate service terminal.

A radio communication system for duplex communication comprising an optical carrier generator for generating optical carrier signals, a local oscillator (LO) for generating an electrical signal in a radio communication band, an information signal source, electro-optic modulators driven directly at an input electrical port by said information signal and said LO signal to modulate a portion of said optical carrier signal to form a modulated portion being an optical band information signal for transmission over an optical link; and a photodetector remote from said electro-optic modulators for receiving said transmitted optical band information signal from said optical link, and directly generating an electrical signal that is up-converted for radio transmission, or down-converted to a baseband frequency.

The present application relates to devices and components related to a direct detection and photonics receiver.

The present application relates to devices and components including apparatus, systems, and methods for high-throughput, low-power signaling.

A communication system may an optical signal generator and a signal path. The generator may generate one or more optical local oscillator (LO) signals and an optical frequency comb. Optical paths and an optical demultiplexer may distribute the optical LO signal(s) and the frequency comb to photodiodes in one or more access points. The photodiodes may be coupled to antenna radiating elements. The optical paths may illuminate each photodiode using a signal pair that includes one of the optical LO signals and one of the carriers from the frequency comb. The photodiodes may convey wireless signals using the antenna radiating elements at frequencies given by the differences in frequency between the signals in the signal pairs. The radiating elements may concurrently convey the wireless signals with different external devices at different frequencies, with different devices at the same frequency, and/or with the same device at the same frequency.

A radio communication system for duplex communication comprising an optical carrier generator for generating optical carrier signals, a local oscillator (LO) for generating an electrical signal in a radio communication band, an information signal source, electro-optic modulators driven directly at an input electrical port by said information signal and said LO signal to modulate a portion of said optical carrier signal to form a modulated portion being an optical band information signal for transmission over an optical link; and a photodetector remote from said electro-optic modulators for receiving said transmitted optical band information signal from said optical link, and directly generating an electrical signal that is up-converted for radio transmission, or down-converted to a baseband frequency.

Systems for low power distribution in a power distribution network (PDN) contemplate using multiple low-power conductors to convey power from a power source to a remote sub-unit. The multiple conductors are isolated from one another to help prevent overcurrent conditions in a fault condition. In a first exemplary aspect, the isolation is provided by galvanic isolation. In a second exemplary aspect, the isolation is provided by diodes at the remote sub-units. Further, current sensors may be used at the power source to detect if any of the multiple low-power conductors are carrying current above a defined threshold current. By providing one or more of these safety features, a multiplexer may not be needed at the remote sub-unit, thus providing cost savings while preserving the desired safety features.