摘要 |
<p>A multiple phase modulator which employs no transformers and which is formed as a single circuit array is described. Conventional modulators used transformers which could not be fabricated as integrated circuitry and involved the use of two circuit arrays which caused phase errors. In the simplest form of the invention, i.e. a 4-phase phase modulator circuit, there is a first exclusive OR circuit having a first input to which the carrier wave is fed and a second input to which one of the two base band digital signals is fed. The resultant 2-phase phase modulated signal is halved in frequency by a frequency divider and this signal is then fed to a first input of a second exclusive OR circuit. The second base band digital signal is fed to a second input of the second exclusive OR circuit which also carries out 2-phase phase modulation to provide the desired 4-phase phase modulated signal.</p> |