Balun
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorDavid Westberg
Life of this patent
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Abstract
The present invention relates to a balun circuit that includes means for transforming a balanced input signal to an unbalanced signal and impedance changing means. The means for transforming the balun input signal to an unbalanced output signal is a λ/2-waveguide (30). A first side of the λ/2-waveguide (30) is connected to a second port (P2) of the balun circuit, while a second side of said λ/2-waveguide (30) is connected to a third port (P3) of the balun circuit. The impedance changing means is a λ/4-waveguide (40) of which a first side is connected to a second side of the λ/2-waveguide (30) and a second side is connected to the first port (P1) of the balun circuit.
Claims5
A balun circuit comprising:
- a λ/2 waveguide, a first end of said λ/2 waveguide being connected to a first port of the balun circuit via a first coil, a second end of the said λ/2 waveguide being connected to a second port of the balun circuit via a second coil;
- a first λ/4 waveguide, a first end of the first λ/4 waveguide being connected to said second end of the λ/2 waveguide, a second end of the first λ/4 waveguide being connected to a third port of the balun circuit via a first capacitor;
- and
- biasing means for biasing components in a load connected between said first and second ports of the balun circuit, the biasing means comprising:
- a second λ/4 waveguide, a first end of the second λ/4 waveguide being connected to said first end of the λ/2 waveguide, a second end of the second λ/4 waveguide being connected to a voltage source and to one electrode of a second capacitor, the other electrode of the second capacitor being connected to ground.
Dependencies are inferred from the claim text.