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. 14, 1997
Filed:
Aug. 01, 1996
Simo Murtojarvi, Salo, FI;
Nokia Mobile Phones Ltd., Salo, FI;
Abstract
The useful frequency range of an I/Q diode modulator is increased by adding two capacitors (15, 16) and an inductance (17), or two inductances and one capacitance, as a series-resonant circuit. The capacitors (15, 16) are connected in series and have a zero voltage at their connection point so that the inductance (17) does not influence the oscillator signal. The inductance (17) is chosen so that resonance occurs at the frequency at which leakage across the diodes would otherwise occur, so that the impedance between ground and the diode (4, 5) connection point is very low and, therefore, so is leakage between the mixer outputs. When the diode elements conduct, the voltage at the point between the diodes (4, 5 or 4a, 5a) is connected to both branches of the transformer (8) secondary so that the branches have equal voltages with the same phase. This permits an I/Q modulator or I/Q demodulator for 400 MHz or even 900 MHz frequency to be made with ordinary UHF mixer diodes.