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:
May. 08, 2007
Filed:
Jun. 19, 2002
Chris Snyder, Pleasantville, CA;
Tajinder Manku, Kitchener, CA;
Gareth Weale, New Hamburg, CA;
Lawrence Wong, Markham, CA;
Chris Snyder, Pleasantville, CA;
Tajinder Manku, Kitchener, CA;
Gareth Weale, New Hamburg, CA;
Lawrence Wong, Markham, CA;
Sirific Wireless Corporation, Waterloo, Ontario, CA;
Abstract
This patent describes a method and system which overcomes the LO-leakage problem during modulation and demodulation, common to direct conversion and similar RF transmitters and receivers. This problem is solved using a virtual local oscillator (VLO™) signal which emulates mixing with a local oscillators (LO) signal. The VLO signal is constructed using complementary mixing signals that suppress mixing power in the bandwidth of the input signal, and within the bandwidth of the output frequency. Specifically, mixing is done in two or more stages, using time-varying mixing signals φand φwhich satisfy the following criteria: φ*φhaving significant power at the frequency of the LO being emulated, one of φand φhaving minimal power around the frequency of the output signal y(t), and the other of φand φhaving minimal power around the center frequency, f, of the input signal x(t).