The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1982
Filed:
Jul. 14, 1980
James B Beyer, Madison, WI (US);
James B Summers, Spokane, WA (US);
Wisconsin Alumni Research Foundation, Madison, WI (US);
Abstract
A parallel type modulator is disclosed which utilizes a pair of bi-phase modulators (10), each of which are capable of independent phase and amplitude modulation. In each bi-phase modulator, a carrier frequency signal is split by a power splitter (20) into two signals 180.degree. apart in phase which are passed through directional couplers (30 and 31) and a pair of PIN diodes (35 and 36) to a summing junction (37). A bias source circuit (42) delivers biasing current to the coupled outputs of the directional couplers (30, 31) and through the PIN diodes (35, 36) to the summing junction (37); this current is returned to ground through a bias return circuit (44) which conducts the DC or low frequency biasing signal but allows the carrier frequency output signal to be passed through to the output of each bi-phase modulator. Reduction of the bias current to one diode below null levels at which the intermediate signals cancel will cause a carrier frequency signal to appear at the summing junction which will be in phase with the signal passed through the other diode. A continuous variation of the bias current through one of the diodes at a level below the null current level will result in amplitude modulation of the output signal at the summing junction. The PIN diodes are always operated in their conducting regions so that large parasitic reactances at microwave frequencies are avoided. A parallel modulator can be formed of a pair of the bi-phase modulators provided with carrier frequency signals in quadrature, and with the outputs of each bi-phase modulator being summed to yield an output signal at the carrier frequency which can have an arbitrary phase angle and continuous modulation of amplitude.