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:
Jul. 26, 2005
Filed:
Jun. 08, 2001
Jenshan Lin, Pine Brook, NJ (US);
Jenshan Lin, Pine Brook, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
An active balun circuit is provided for single-ended to differential RF signal conversion with enhanced common-mode rejection which suppresses common mode signal and which achieves phase and amplitude balance without sophisticated tuning or compensation methods. The circuit has a single-ended input and balanced output with phase and amplitude balance error less than 2° and 1.2 dB, respectively, measured from 1.5 GHz to 1.8 GHz at 5V supply. When supply voltage drops down to 1.5V, its phase and amplitude balance error remains within 5° and 2 dB, respectively. The circuit achieves a balanced output via an output network which behaves as an impedance matching network for differential mode signal and is grounded for common mode signal. As a result, common mode signal is suppressed and 180-degree phase balance at output is achieved. The circuit has high-linearity (P1 dB=5 dBm, IIP3=16.6 dBm) and low residual phase noise (<−155 dBc/Hz at 100 kHz and above) which make it suitable as an active balun/buffer amplifier between LO and balanced mixer for base station receiver applications.