Design of a Wideband Balun Using IPD Technology for Compensating the Frequency Dependency

In this paper, we propose a wideband balun using integrated passive device (IPD) technology. The proposed circuit is designed to compensate for the magnitude deviations by differentiating the magnitude S-parameter and calculating the lumped component value when the derivative value is zero. For a smaller size, the proposed circuit is implemented using IPD technology, and the fabricated circuit’s size is 2.4 mm × 1.02 mm. The magnitude of the measurement results has 3.5 ± 0.3 dB deviations from 2.8–4.58 GHz, and the phase difference has 180° ± 10° from 2.8–5 GHz at the center frequency of 3.6 GHz. Therefore, the measurement results show that the theory of the proposed circuit is well matched compared with the measurement results for smaller sizes, wideband magnitude, and phase characteristics.