Qualcomm Incorporated

Hongyan Yan

Bhushan Shanti Asuri

Vinod Panikkath

Himanshu Khatri

Janakiram Ganesh Sankaranarayanan

Chinmaya Mishra

Junxiong Deng

Maulin Pareshbhai Bhagat

Aristotele Hadjichristos

Aleksandar Miodrag Tasic

Rajagopalan Rangarajan

Zhang Jin

Thomas Myers

Guy Klemens

Mohammad Farazian

Ockgoo Lee

Norman L Frederick

Vinod V Panikkath

Maulin Bhagat

The mixer of a transmit chain of a wireless transmitter (such as the transmitter of a cellular telephone handset) is driven with low third harmonic in-phase (I) and quadrature (Q) signals. The low third harmonic I and Q signals have three or more signal levels, and transition between the these three or more signal levels at times such that each of the I and Q signals approximates a sine wave and has minimal third harmonic spectral components. In one example, reducing the third harmonic components of the I and Q signals simplifies design of amplifier stages of the transmitter and helps reduce receive band noise.

Driving a mixer with a differential lo signal having at least three signal levels

An adaptable mixer device is operable in a first mode and a second mode and includes a first set of mixer units operable in the first mode and a second set of mixer units operable in the second mode. The second set of mixer units includes at least one mixer unit that is common to both the first set of mixer units and the second set of mixer units. The second set of mixer units also includes a plurality of mixer units that are not in the first set of mixer units. Similarly, the first set of mixer units including a plurality of mixer units that are not in the second set of mixer units.

Adaptable mixer and local oscillator devices and methods

Disclosed are circuits, techniques and methods for implementing an attenuator in a signal transmission path. In one particular implementation, an attenuation may be adjusted based, at least in part, on a control signal. In another implementation, such an attenuation may be adjusted in coarse increments by varying one or more gate voltages applied one or more transistors. In yet another implementation, adjusting said attenuation in fine increments by varying a bias voltage applied to at least one level shifter.

Programmable attenuator

An integrated circuit is described. The integrated circuit includes an inductor that has a large empty area in the center of the inductor. The integrated circuit also includes additional circuitry. The additional circuitry is located within the large empty area in the center of the inductor. The additional circuitry may include a capacitor bank, transistors, electrostatic discharge (ESD) protection circuitry and other miscellaneous passive or active circuits.

Methods and apparatus for inductors with integrated passive and active elements

In a first aspect, an RF switch includes a main transistor and a gate-to-source shorting circuit. When the RF switch is turned off, the gate-to-source shorting circuit is turned on to short the source and gate of the main transistor together, thereby preventing a Vgs from developing that would cause the main transistor to leak. When the RF switch is turned on, the gate-to-source shorting circuit is turned off to decouple the source from the gate. The gate is supplied with a digital logic high voltage to turn on the main transistor. In a second aspect, an RF switch includes a main transistor that has a bulk terminal. When the RF switch is turned off, the bulk is connected to ground through a high resistance. When the RF switch is turned on, the source and bulk are shorted together thereby reducing the threshold voltage of the main transistor.

RF isolation switch circuit

An RF transmitter capable of transmitting over a wide range of frequencies includes a mixer, a wideband high-Q balun, a first driver amplifier and a second driver amplifier. The balun has a single primary winding and two secondary windings. A differential output of the mixer is coupled to the primary winding. A first of the two secondary windings is coupled to drive the first driver amplifier. A second of the two secondary windings is coupled to drive the second driver amplifier. One driver amplifier is used when transmitting at lower frequencies whereas the other driver amplifier is used when transmitting at higher frequencies. By appropriate sizing of the inductances of the secondary windings and by switching out one of the secondary windings at certain times, the balun is tunable to operate over the wide frequency range while having a high quality factor Q, thereby facilitating reduced power consumption while simultaneously meeting performance requirements.

Wideband balun having a single primary and multiple secondaries

A circuit for a voltage controlled oscillator (VCO) buffer is described. The circuit includes a first capacitor connected to an input of the VCO buffer that is connected to a VCO core. The circuit also includes a second capacitor connected to the input of the VCO buffer and the gate of a p-type metal-oxide-semiconductor field effect (PMOS) transistor. The circuit further includes a first switch connected to the first capacitor and the gate of the PMOS transistor. The circuit also includes a third capacitor connected to the input of the VCO buffer. The circuit further includes a fourth capacitor connected to the input of the VCO buffer and the gate of an n-type metal-oxide-semiconductor field effect (NMOS) transistor. The circuit also includes a second switch connected to the third capacitor and the gate of the NMOS transistor.

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San Diego, CA, United States of America

Hongyan Yan