LTCC stripline resonator using embedded air cavities for millimeter wave applications

Abstract

tennas and filters for all three cases. Figure 8(d) shows the measured S11 response from the FSH13 network analyzer. As can be seen, the hairpin and hybrid filter both use 1500 mm 2 of laminate and both have similar S11 responses. This would indicate that the hybrid filter could be used as an alternative to the hairpin. It should be noted that the patch antenna integrated with the filters, had a narrower bandwidth than the filters, thus the S11 responses measured in Figure 8(d) are dominated by the antenna. It is left for future work to investigate the performance of the filters with antennas that have broader band-widths. CONCLUSIONAs can be seen from Figures 4 -6, there is good agreement between the measured and simulated responses. Thus the empirical approach of designing a filter using the optimization features of software is validated. All filters were designed for five resonators, however, for the hybrid and folded cases, there is additional coupling between nonadjacent resonators. Thus intermediary resonators are partially bypassed, lowering the effective filter order, thus as seen in Figure 7 the hybrid and folded filter have reduced isolation and selectivity. The use of HTS materials results in resonators having higher Q factors. It is left to a later project to investigate the effect of HTS materials upon these filters however we expect the sidebands become unobservable and that the filter selectivity improves. ABSTRACT: A stripline T-resonator is designed and implemented in the LTCC substrate for millimeter wave applications. The loss-free aircavities are embedded at both side edges of the conducting strip in order to efficiently reduce the dielectric loss of the stripline structure. The resonator was implemented using 4-layer LTCC dielectrics. The fabricated stripline resonator with air cavities reveals Q-factor of 248 and total loss of 0.035 dB/mm at 34.7 GHz, and that is improved by 108% and 51%, respectively, compared to the conventional one. The proposed LTCC stripline resonator with the embedded air cavities can meet demands for low-loss millimeter-wave system-on-package (SoP) applications. Figure 8 (a) Hairpin filter integrated with Patch Antenna, (b) hybrid filter integrated with patch antenna, (c) folded filter integrated with patch antenna, (d) comparison of filters integrated with patch antennas 658