Apple Inc.

Freescale Semiconductor,inc.

Fujitsu Semiconductor Limited

Intel IP Corporation

Stephen Rector

Omid Oliaei

Chuanzhao Yu

Kurt Hausmann

Cristiano Benevento

Wideband signal buffers that can be employed for mmWave (millimeter wave) communication are disclosed. One example signal buffer comprises a variable gain amplifier (VGA) that receives two control words and outputs a feedback signal, wherein both an amplitude and a phase of the feedback signal are based on the two control words and on a bias voltage; and a matching network comprising a first inductor that outputs the bias voltage, a second inductor, and a third inductor that receives the feedback signal from the VGA, and wherein the first, second, and third inductors are magnetically coupled to each other, wherein the signal buffer is configured to receive a RF (Radio Frequency) input and to generate a RF output from the RF input based on a transfer function of the signal buffer, wherein the transfer function is based at least in part on the feedback signal.

Wideband signal buffer

In accordance with some embodiments of the present disclosure, a method may include generating a first current equal to a bandgap voltage divided by a resistance selected to approximately match a process resistance integral to a receiver. The method may further include generating a second current equal to temperature-dependent current multiplied by a predetermined scaling factor. The method may also include subtracting the second current from the first current to generate a bias current. The method may additionally include providing the bias current to the receiver.

System and method for reducing or eliminating temperature dependence of a coherent receiver in a wireless communication device

Method and apparatus are provided for linearized balanced signal mixing. A signal mixing circuit () for translating a radio frequency (RF) signal is provided comprising an input amplifier (), a mixer network (), and an output buffer amplifier (). The input amplifier () is configured to produce an amplified RF signal and cancel an input third-order intermodulation (IM) distortion in the amplified RF signal with a cross-coupled feedback amplifier (). The mixer network () is configured to produce an intermediate frequency (IF) signal based on the amplified RF signal and a local oscillator signal. The output amplifier () is configured to buffer the IF signal and cancel an output IMdistortion in the IF signal with a cross-coupled feedback amplifier (). The input amplifier () and cross-coupled feedback amplifier () also serve as a bias current source for the mixer network (), thus lowering the supply voltage required for the mixing circuit ().

Linearized and balanced mixer apparatus and signal mixing method

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Tempe, AZ, United States of America

Stephen Rector