Patent
Method and apparatus for generating a linearly modulated signal using polar modulation
Bengt Lindoff,Hakan Eriksson +1 more
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TLDR
In this article, an apparatus and method for generating a linearly modulated signal in a polar modulation system is described, where a signal for transmission is separated into a phase component and an amplitude component, and a carrier signal is modulated with the phase component in a phase modulator, creating a phase distortion.Abstract:
An apparatus and method generate a linearly modulated signal in a polar modulation system. A signal for transmission is separated into a phase component and an amplitude component, and a carrier signal is modulated with the phase component in a phase modulator, creating a phase distortion. A compensator compensates for the phase distortion created by the phase modulator by modifying the amplitude component. The phase modulated carrier signal is amplitude modulated by the compensated amplitude component to produce a linearly modulated signal.read more
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References
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Journal ArticleDOI
Delta-sigma modulation in fractional-N frequency synthesis
TL;DR: In this article, a delta-sigma (Delta-Sigma) modulation and fractional-N frequency division technique for indirect digital frequency synthesis using a phase-locked loop (PLL) is described.
Patent
Linearized power amplifier
Michael Faulkner,M.A. Briffa +1 more
TL;DR: In this paper, a linearized power amplifier is provided which comprises a non-linear radio frequency (RF) power amplifier, a linearization circuit such as a Cartesian Feedback circuit, an RF feedback circuit; an IF feedback circuit, or a feedforward circuit, and a dynamic bias modulation circuit for modulating an operating voltage of the amplifier.
Patent
Power amplifier having nested amplitude modulation controller and phase modulation controller
TL;DR: In this paper, the amplitude modulated (AM) and phase modulation (PM) components are nested about a power amplifier (PA), allowing the PM control loop to correct for any distortion introduced by the PA.
Patent
Modulation system capable of improving a transmission system
TL;DR: In this paper, a modulation system responsive to a system input signal for supplying an amplifier having nonlinearities with a modulated analog signal to make the amplifier produce an amplified output signal is presented.
Journal ArticleDOI
A simplified continuous phase modulator technique
T.A.D. Riley,M.A. Copeland +1 more
TL;DR: A low cost GMSK (Gaussian minimum shift keying) modulation technique is presented, suitable for any continuous phase constant envelope modulation with discriminator, differential or coherent detection in the targeted receiver.