Design of wideband LC balun embedded into organic substrate using coupled LC resonators

Abstract

In this paper, wideband LC balun using coupled LC resonator has been designed, simulated and fabricated for being embedded into an organic packaging substrate. The proposed balun has a novel scheme which consists of two pair of coupled embedded LC resonators which share one resonator with each other. The coupled resonators are applied to obtain a precise phase difference of 180 degree and an identical magnitude between two balanced ports. This proposed balun has relatively small inductance and capacitance values which can be easily embedded into the organic packaging substrate. The capacitors at embedded LC resonators were realized by using high dielectric BTO composite film. The measured result shows that fabricated balun has excellent phase and magnitude imbalanced characteristic. The measured results are an insertion loss of 1.8 dB, a return loss of 10 dB, a phase imbalance of 0.5 degree and magnitude imbalance of 0.7 dB at frequency bandwidth of 700 MHz ranged from 1.8 GHz to 2.5 GHz, respectively. The fabricated balun has a volume of 2mm×3.5mm×0.66mm (height). The measured result was well agreed with the simulated results.Index Terms-Wideband balun, Coupled LC resonator, SOP, organic package substrate, high dielectric composite, inductor, capacitor

Balun-BPF using magnetically coupled interdigital-loop resonators

“…In the microwave circuit, a Balun connects the device using a balanced-signal to the device using the unbalanced signal [1][2][3]. In the operating frequency range, 2 output terminals have the phase difference of 180 degrees in the same magnitude [1][2][3].…”

“…In the operating frequency range, 2 output terminals have the phase difference of 180 degrees in the same magnitude [1][2][3]. Moreover, in the high frequency circuit, signal flow is general to pass a Balun, and the BPF and flow in LNA(low noise amplifier) or MIC(microwave integrated circuit), the signal coming in through an antenna is.…”

“…The synthesis exists in the passive elements of the RF front-end including Balun, BPF, antenna, and etc. with one of the method for raising the integration of the passive elements [1][2][3].…”

“…The research exists that it inserts the additional capacitance into the existing hairpin or the slow-wave resonator and it miniaturizes [4][5]. The Balun-BPF using the magnetically coupled resonator, which is one of the composition methods of , an inductor has to be replaced with a resonator [1][2]. Fig.2 shows the structure of the proposed Balun-BPF.…”