Title: Modulator comprising a dual-frequency oscillator and a synthesizer
Application Number: 200580023527 Application Date: 2005.07.01
Publication Number: 1985437 Publication Date: 2007.06.20
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03C3/09;H03C3/22;H03B25/00;H03B5/12
Applicant(s) Name: Koninkl Philips Electronics NV Address:
Inventor(s) Name: Kerselaers Anthony;Elsen Felix
Attorney & Agent: wangyue liujie
Abstract:
    Oscillators (10) which oscillate at a fundamental frequency also generate harmonics. The fundamental frequency or a lower harmonic is used for feedback purposes, and a harmonic higher than either the fundamental frequency or the lower harmonic is used for output purposes. As a result, the oscillators (10) operate at a lower frequency than an output frequency and are low cost. Synthesizers (20) coupled to the oscillators (10) also operate at this lower frequency, and modulators (5) comprising such oscillators (10) and synthesizers (20) are low cost. A lower power consumption and less sensitivity to disturbing fields are further advantages. Filtering has become less complicated, and a smaller number of components has resulted in smaller dimensions. The oscillators (10) comprise tuning circuits (11) and amplifiers (12), which amplifiers (12) are fed back via feedback circuits (13). Such an amplifier (12) may comprise just a single transistor (40).
Time: 11