Patent ID: 7864014
Filing Date: 2011-01-04
Classification: H01F,H01P,H03H

Abstract:
1. A mode-switching transformer comprising a first line in common mode and a second line in differential mode, each line comprising two sections in series respectively coupled with one of the two sections of the other line and all sections having the same lengths, wherein the common mode line is connected in series with a capacitor, to lower a central frequency of a bandwidth of the transformer, the λ/4 lengths of the sections being chosen to correspond to a central frequency greater than a desired central frequency for the transformer; wherein the value of capacitor C respects the following relation: where f 0 designates the desired central frequency, where L designates the length of the two sections in series calculated in λ/2 from said central frequency greater than the desired central frequency, where Z c designates the characteristic line impedance, and where β designates the phase constant.