H04B2001/485

Radio frequency switch branch circuitry

Disclosed is radio frequency switch circuitry that includes a switch branch having a first branch terminal coupled to a first signal port and a second branch terminal coupled to a second signal port, and a branch control terminal, wherein the switch branch has both an on-state and an off-state to control passage of a radio frequency signal between the first signal port and the second signal port in response to a control signal applied to the control terminal. The radio frequency switch circuitry further includes an isolation inductor coupled between the first branch terminal and the second branch terminal such that the isolation inductor is in parallel with the switch branch, wherein the isolation inductor has a given inductance that provides resonance with a total off-state capacitance of the switch branch in the off-state at a center frequency of the radio frequency signal.

Electronic module

The present disclosure provides an electronic module including a circuit including a transmitting part and a receiving part physically separated from the transmitting part. The electronic module also includes an element isolated from the circuit and configured to block electrical interference between the transmitting part and the receiving part.

Second Order Harmonic Cancellation for Radio Frequency Front-End Switches
20200136669 · 2020-04-30 ·

A radio frequency switch circuit with improved harmonic suppression and low insertion loss has an antenna port and a plurality of signal ports. A plurality of transistor switch circuits, are connected to a respective one of the plurality of signal ports and to the antenna port. Each of the transistor switch circuits has a transistor, which in an off state, together with a harmonic suppression capacitor and a parallel inductor both connected thereto, define a tank circuit that suppresses RF signals applied to the corresponding transistor switch circuit from a different one of the transistor switch circuits. The harmonic suppression capacitor is tuned to distribute large signal voltage swings in the RE signal amongst parasitic diodes of the transistor.

Independent control of branch FETs for RF performance improvement

A FET-based RF switch architecture and method that provides for independent control of FETs within component branches of a switching circuit. With independent control of branch FETs, every RF FET in an inactive branch that is in an open (capacitive) state can be shunted to RF ground and thus mitigate impedance mismatch effects. Providing a sufficiently low impedance to RF ground diminishes such negative effects and reduces the sensitivity of the switch circuit to non-matched impedances.

RF signal separation and suppression system and method

A method of separating a desired signal from an undesired signal includes obtaining a total input signal comprising the desired signal and the undesired signal in a time domain occupying a time duration from time t.sub.1 to time t.sub.2 of a single symbol in the desired signal. A transform is performed of the total input signal wherein an output of the transform is a time domain signal representing the desired signal.

Determining redundant radios

An algorithm for determining redundant radios in APs is disclosed. The algorithm first performs a coverage peak flattening algorithm to predict an impact to the total coverage area if a radio in a selected AP does not transmit signals in a frequency band. If the impact to the total coverage area is acceptable, the algorithm then performs a multi-point check algorithm to determine whether the radio in the selected AP is redundant in the frequency band. After determining that the radio in the selected AP is redundant in the frequency band, the algorithm transforms the redundant radio into various services based on the network deployment and user preference.

SECOND-ORDER HARMONIC REDUCTION FOR RADIO FREQUENCY TRANSMITTER
20200091955 · 2020-03-19 ·

Certain aspects of the present disclosure provide methods and apparatus for simultaneous multi-band transmission, including techniques and circuitry for reducing the coupling of a second-order harmonic signal into a victim circuit. One example radio frequency front-end circuit generally includes a first transmit output stage circuit configured to output signals in a first frequency band and a second transmit output stage circuit configured to output signals in a second frequency band. The first transmit output stage circuit generally includes a first adjustable transconductance stage comprising an input stage and a cascode stage coupled to the input stage; and a first adjustable impedance stage coupled to the first adjustable transconductance stage. For certain aspects, the second transmit output stage circuit generally includes a second adjustable transconductance stage and a second adjustable impedance stage coupled to the second adjustable transconductance stage.

Radio frequency switch system

A radio frequency switch system includes a plurality of radio frequency switch circuitries that each include a switch branch coupled between a first branch terminal and a second branch terminal and are configured to allow passage of a radio frequency signal through the switch branch in an on-state and to block the radio frequency signal from passing through the switch branch in an off-state in response to a control signal applied to a branch control terminal of the switch branch. Also included is a switch controller configured to apply the control signal to the branch control terminal of the switch branch of each of the plurality of radio frequency switch circuitries, wherein the control signal has a first voltage level that places the switch branch in the on-state and a second voltage level that places the switch branch in the off-state without digital signal decoding of the control signal.

Multiplexer with switched filter branch including high-Q components

A multiplexer includes a common port, multiple filter branches and at least one switch included in a switched filter branch of the multiple filter branches. The filter branches are connected to the common port, and each filter branch corresponds to at least one predetermined frequency band and filters a radio frequency (RF) signal according to the corresponding at least one predetermined frequency band. In a first switch state of the at least one switch, the switched filter branch includes a high-Q filter having multiple high-Q components for improving roll-off of the filtered RF signal, and in a second switch state of the at least one switch, the switched filter branch includes a low-Q filter having multiple low-Q components that support a very high bandwidth for filtering the RF signal.

Multistage amplifier linearization in a radio frequency system

A linearization circuit reduces intermodulation distortion in an amplifier that includes a first stage and a second stage. The linearization circuit receives a first signal that includes a first frequency and a second frequency and generates a difference signal having a frequency approximately equal to the difference of the first frequency and the second frequency, generates an envelope signal based at least in part on a power level of the first signal, and adjusts a magnitude of the difference signal based on the envelope signal. When the amplifier receives the first signal at an input terminal, the first stage receives the adjusted signal, and the second stage does not receive the adjusted signal, intermodulation between the adjusted signal and the first signal cancels at least a portion of the intermodulation between the first frequency and the second frequency from the output of the amplifier.