Motorola Corporation

Freescale Semiconductor,inc.

Motorala, Inc.

Daniel E Brueske

David B Harnishfeger

Robert E Stengel

David E Bockelman

Frederick L Martin

Richard B Meador

David J Graham

Babak Bastani

Gary A Kurtzman

Vance H Peterson

Stephen T Machan

A zero intermediate frequency (ZIF) radio frequency (RF) digital mixer () includes a low noise amplifier (LNA) (), a first RF mixer stage () for mixing an RF signal from the at least one LNA with a first local oscillator signal operating a first predetermined frequency. A second RF mixer stage () is then utilized for mixing in-phase (I) and quadrature (Q) digital signals from the first RF mixer stage () with a plurality of second local oscillator signals (LO) operating at a second predetermined frequency. The invention significantly improves current drain by eliminating the need for a linear transconductance stage while still maintaining high degrees of isolation and linearity.

Dynamic power sharing zero intermediate frequency (ZIF) mixer and method of forming same

A voltage controlled oscillator (VCO) for use in a personal area network synthesizer includes a delay cell (), a first current amplifier () for amplifying an input current, a resister capacitor (RC) tuning network () for varying the amount of amplification and delay of an output of the first current amplifier. A second current amplifier () is then used for amplifying an output current from the RC tuning network. The invention includes a unique composite voltage variable capacitor (CVVC) () for precisely tuning the amount of delay presented by the delay cell. The unique topology of the delay cell () allows it to be readily used in voltage controlled oscillators (VCOs) operable at frequencies above 1 GHz.

Two port voltage controlled oscillator for use in wireless personal area network synthesizers

A system for coarsely tuning at least one voltage controlled oscillator (VCO) ( ) in a phase locked loop (PLL) synthesizer ( ) that includes a phase-frequency detector (PFD) for determining a phase difference between a VCO frequency and a reference frequency and providing an error signal if the VCO frequency and reference frequency are at least 2&pgr; radians out of phase. A monitor ( ) is then used for tracking the number of error signals produced by the PFD. The free running frequency of the VCO may be coarsely tuned in the event the monitor circuit reaches some predetermined level. The invention offers great advantage in enabling a PLL to be coarsely tuned to enable the PLL's VCO to remain with an operational range despite operational factors that effect circuit operation.

System and method for coarse tuning a phase locked loop (PLL) synthesizer using 2-PI slip detection

A dynamic range on demand radio frequency (RF) receiver ( ) includes a wideband detector ( ), off-channel detector ( ) and on-channel detector ( ) supplying input to an automatic gain control ( ) for adjusting a dynamic control stage to control dynamic range and resolution of digital baseband signals ( ).

Dynamic range on demand receiver and method of varying same

A gain controllable low noise amplifier (LNA) (,) with automatic linearity enhancement utilizes an amplifier stage (,) for amplifying a radio frequency (RF) input signal and a dynamically controllable feedback loop amplifier stage (,) for providing negative feedback to the feedback amplifier. A bias controller (,) is coupled to the dynamically controllable feedback loop amplifier stage (,) for monitoring a receiver automatic gain control (AGC) system (,) and providing a dynamic bias to the feedback loop amplifier stage (,) to improve linearity to the LNA in the presence of strong on-channel and off-channel signal conditions.

Gain controllable low noise amplifier with automatic linearity enhancement and method of doing same

The invention produces an accurate quadrature relationship for a range of frequencies using passive components in the primary quadrature splitting circuits. A reference oscillator (,) generates a reference signal which is fed to a conventional passive quadrature splitter circuit (,). However, since the reference circuit provides signals over a range of frequencies, the output signals of the passive quadrature splitter may not have an accurate quadrature relationship. The output signals of the passive quadrature splitter are then equalized in magnitude, and the sum and difference of the signals are produced, which will be in an accurate quadrature relationship.

Apparatus and method for generating accurate quadrature over a frequency range

A wideband phase-lock loop frequency synthesizer (200) used in a radio transceiver capable of being reconfigured to operate in either a transmit, receive, or battery save mode. The wideband phase-lock loop frequency synthesizer (200) includes, a divide-by-two divider (205), quadrature detector (204), offset VCO (209) and offset mixer (207) for generating a quadrature phase modulated signal. Moreover, a programmable filter (211) is used for removing predetermined harmonic components of the offset mixed signal enabling the synthesizer to operate over a wide frequency range.

Wideband frequency synthesizer for direct conversion transceiver

A wideband fully integrated two-way radio transmitter (100) includes a voltage controlled oscillator (VCO) (101) for providing a voltage at a radio frequency. A divider (103) is used reducing the radio frequency (RF) signal from the VCO to a an intermediate frequency. A voltage-to-current converter is used for changing the voltage of the intermediate frequency RF signal to an RF current. A transmit buffer is then used for amplifying the RF current supplied by the voltage-to-current converter for amplification by a power amplifier. The fully integrated current mode transmit buffer offers the advantage of amplification over a large bandwidth while providing isolation between the transmit buffer and the VCO.

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Plantation, FL, United States of America

Daniel E Brueske