Sirific Wireless Corporation

Icera Canada Ulc

Yang Ling

Tajinder Manku

Lawrence Wong

William Kung

An inexpensive, high-performance, fully-integrable, multi-standard transceiver with a topology including: an active mixer, followed by a high pass filter, and a passive mixer. The input signal is modulated up, or demodulated down, using a pair of complementary, aperiodic mixing signals. The use of aperiodic mixing signals allows a fully-integrated transceiver to be built. Embodiments of the active mixer include those having electrically-adjustable performance and allowing multiple RF signal inputs. This allows the topology to be employed in multi-band, multi-frequency applications, while still providing high performance.

Method and apparatus for conversion of radio frequency (RF) signals using aperiodic mixing signals

This patent describes a method of removing the LO-leakage and 1/f noise problems associated with direct conversion RF receivers and other demodulators. In order to solve this problem a virtual LO&#x2122; signal is generated within the RF signal path which is tuned to the incoming RF signal. The virtual local oscillator (VLO) signal is constructed using signals that do not contain a significant amount of power (or no power at all) at the LO frequency. Any errors in generating the virtual LO signal are minimized using a closed loop correction scheme.

Method and apparatus for down-conversion of radio frequency (RF) signals with reduced local oscillator leakage

The invention describes improvements to a balanced active demodulator subsystem implemented in Radio Frequency integrated circuit technology that simplify the configuration and set-up of a balanced demodulator section and reduce the labor and time required during manufacture to adjust the demodulation characteristics for optimum performance. The subsystem allows for the selection of various combinations of components during use, during configuration and set-up, or during both phases, and comprises a mixer, a plurality of parallel RF balanced amplifier input stages operationally connected to the mixer, a first set of switches arranged to permit the independent selection and making operable one of the RF balanced amplifier stages, a number of pairs of current sources arranged to provide bias currents for the RF balanced amplifier input stages to reduce the current required to be passed through the balanced demodulator section; and a second set of switches arranged to permit the independent selection and making operable one of said pairs of current sources. The invention provides a balanced demodulator subsystem suitable for use in products in which cost-effectiveness is a critical factor, such as those used in personal communications.

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Waterloo, Canada

Yang Ling