Title: Two-point modulation type phase modulating apparatus, polar modulation transmitting apparatus, radio transmitting apparatus, and wireless communication apparatus
Application Number: 200680000421 Application Date: 2006.04.21
Publication Number: 1977507 Publication Date: 2007.06.06
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H04L27/20;H03C3/00;H03C3/09;H03L7/18;H04B1/04
Applicant(s) Name: Matsushita Electric Ind Co., Ltd. Address:
Inventor(s) Name: Hirano Shunsuke;Adachi Hisashi
Attorney & Agent: shaoya li lixiao shu
Abstract:
    There provides a two-point modulation phase modulation apparatus capable of obtaining an RF phase modulation signal of superior modulation precision with low power consumption and a simple configuration even in the event of inputting a wide band baseband modulation signal. A differentiator ( 21 ) of the opposite characteristics to the attenuation characteristics of anti-alias filter ( 22 ) is provided at the front stage of a D/A converter ( 6 ). As a result, it is possible to sufficiently suppress an alias signal without raising the sampling frequency of the D/A converter ( 6 ) (i.e. low power consumption) using an anti-alias filter ( 22 ) of a simple configuration (i.e. low cost) with a low order for a narrower bandwidth than a PLL modulation frequency bandwidth, and it is possible to obtain an RF phase modulation signal where the entire frequency band of input digital baseband modulation signal (S 1 ) is reflected in a superior manner.
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