Motorola Corporation

Motorola Mobility LLC

Gregory S Raven

Jose E Korneluk

George C Anderson

Frederick L Martin

Jeffrey A Rollman

A multi-mode communication device () uses a quadrature transmitter () for transmitting both amplitude and constant envelope angle-modulated signals. For angle modulation, a separate feedback path is used from that used for amplitude modulated signal transmission. An FM receiver () is used to produce error signals () used in correcting the I and Q quadrature signals ().

Method and apparatus for generating constant envelope modulation using a quadrature transmitter

A quadrature modulated transceiver () is used to generate a constant envelope angle modulated signal for communications. To produce the required feedback when operating in the constant envelope mode, an orthogonal frequency division multiplexed receiver () is used.

Multi-mode communication device for generating constant envelope modulated signals using a quadrature modulator

A frequency generation device (,) comprises a cascade of two phase-locked loops (,and,). The first PLL (,) is a frequency synthesizer while the second PLL, or offset loop (,), comprises a phase detector (,or,), loop filter (,or,), VCO (,or,) and a divider with near-unity modulus (,or,). In the case of a negative offset design, the near-unity divider (,) is placed in the offset loop feedback path. In a positive offset design, the near-unity divider (,) is placed in the path between the synthesizer VCO and the offset loop phase detector. Unlike existing art, there is no offset signal input to the second or offset loop (,).

Method and apparatus for producing an offset frequency

An amplification device (18) has its gain controlled by varying the current flowing into the amplification device. The current is varied (36) by a means of a variable bias network that adapts the input current in response to a control signal. In this way, the amplification device is provided with variable gain while avoiding parametric regeneration.

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Plantation, FL, United States of America

Gregory S Raven