Compact broadband impedance transformer

摘要

The present invention is directed to an impedance transformation device for use in a system having a characteristic system impedance, the device being characterized by a predetermined bandwidth having a center frequency. The device housing size is one-eighth wavelength of the center frequency. A first coupler is characterized by an even mode impedance and an odd mode impedance. The bandwidth is a function of the even mode impedance and the odd mode impedance substantially corresponds to the component port impedance. At least one second coupler is disposed in parallel with the first coupler and is characterized by the even mode impedance and the odd mode impedance.

主权项

1. An impedance transformation device for use in a system having a characteristic system impedance, the device being characterized by a predetermined bandwidth having a center frequency, the device comprising:
a housing including an interior region characterized by a size substantially corresponding to a one-eighth wavelength of the center frequency, the housing including a plurality of input/output (I/O) ports, the plurality of I/O ports including a first port configured to be coupled to a system component characterized by a component port impedance, and a second port configured to be coupled to the system impedance, an impedance transformation ratio of the component port impedance and the system impedance; a first coupler disposed in the interior region and including a first transmission line and a second transmission line, first transmission line being coupled between the first port and the second port, the first transmission line and the second transmission line having a predetermined geometry disposed in a stripline broadside arrangement, the first coupler being characterized by an even mode impedance and an odd mode impedance, the bandwidth being a function of the even mode impedance and the odd mode impedance substantially corresponding to the component port impedance; and at least one second coupler disposed in the interior region substantially in parallel with the first coupler, the at least one second coupler including a third transmission line and a fourth transmission line having the predetermined geometry disposed in the stripline broadside arrangement, the at least one second coupler being characterized by the even mode impedance and the odd mode impedance.