The theory of synchronous Branch-line conpler is used for the immittances of 3-dB Branch-line coupler. After driving the immittance of the line, each transmission line is changed to the eguivalent L.C circuit by using the image impedance.
A 3 branch...
The theory of synchronous Branch-line conpler is used for the immittances of 3-dB Branch-line coupler. After driving the immittance of the line, each transmission line is changed to the eguivalent L.C circuit by using the image impedance.
A 3 branch, 3-dB coupler of which bandwidth is 24% and directivity is greater than 20dB is constructed at 900 MHZ in lumped capacitor and transmission-line inductor. Experimental results are in excellent agreement in coupling over the 24% bandwith but directivity is not in good agreement because of the incorrect capacitors. And the circuit area is reduced to less than 15% of conventional transmission-line realization.