Design of the micro lumped balun based on LTCC technology

This paper presents a method to realize the micro lumped balun based on LTCC technology. The circuit of balun adopts the three port network structure. With the circuit simulation and 3D electromagnetic field simulation software, realize the design of narrow-band balun. Good agreements were found between the test and simulation results. The center frequency is 925MHz, its bandwidth is 80 MHz and its insertion loss is less than 4.39dB in the pass band, two output port signal amplitude difference less than 0.35 dB, phase difference of 180°±4°, The size of balun is only 4.5mm×3.2 mm×1.5 mm. With the low frequency and long wavelength of the balun, it belongs to the UHF band, and lumped structure is used for the design to make it miniaturization.