Multifunctional substrates for high-frequency applications

2005

In this paper, we demonstrate the development of advanced 3-D low-temperature cofired ceramic (LTCC) system-on-package (SOP) passive components for compact, low cost millimeter-wave wireless front-end modules. Numerous miniaturized easy-to-design passive circuits that can be used as critical building blocks for millimetre-wave SOP modules have been hereby realized with high performance and high integration potential. One miniaturized slotted patch resonator has been designed by the optimal use of vertical coupling mechanism and transverse cuts and has been utilized to realize compact duplexers (39.8 GHz/59 GHz) and 3 and 5 poles band pass filters by the novel 3D (vertical and parallel) deployment of single-mode patch resonators. Measured results agree very well with the simulated data. Also, one multiplexing filter, called directional channelseparation filter, that can be used in mixer applications shows insertion loss of <3dB over the bandpass frequency band and a rejection ~ 25dB at around 38.5GHz over the band rejection section. LTCC fabrication limitations have been overcome by using vertical coupling mechanisms to satisfy millimetre-wave design requirements. Last, a double fed cross-shaped microstrip antenna has been designed for the purpose of doubling the data throughput by means of a dual-polarized wireless channel, covering the band between 59-64 GHz. This antenna can be easily integrated into a wireless millimeterwave link system. Index Terms -patch resonator, duplexer, low-temperature co-fired ceramic (LTCC), system-on-package (SOP), directional filter, multiplexing, 3D/vertical integration, microstrip antenna, dual polarization, millimeter-wave (mmW)

Microwave and Optical Technology Letters, 2007

IEEE Transactions on Components, Packaging and Manufacturing Technology, 2011

This paper presents advanced multilayer (ML) thick film system-on-package (SOP) technology for realization of ceramic-based embedded coplanar waveguide (CPW) inductors and capacitors library with remarkably high performance and miniaturization. The detailed characterization and modeling of CPW-lumped components in low-cost photoimageable thick film technology is reported. The passive components are developed with impressive measured self-resonance frequency (SRF) of more than 40 GHz. The newly developed inductors are highly miniaturized and measurements in single (2-D) and double layers (3-D) show inductance value from 0.6 nH to as high as 30 nH for one to eight turns, and with SRF > 40 and 2 GHz, respectively. The quality factor ( Q) for small value inductors is better than 100 and that for the 30 nH inductor is better than 30. The 30 nH inductor measures only 1.3 mm × 1.3 mm × 0.7 mm and demonstrates highest level of miniaturization in ceramicbased multichip module (MCM) technology. Metal-insulatormetal capacitors have been designed and modeled, for single and number of pairs of parallel plates employing horizontally, with increased capacitance and high SRF > 40 GHz. Based on the models developed for the ML lumped components a miniaturized fifth order CPW-based embedded lowpass filter is designed and developed for IF applications with a cut-off frequency of 3.5 GHz. The filter is miniaturized with remarkably low insertion loss of 0.3 dB and stop band attenuation better than 40 dB at 7 GHz. The measured response characteristics are in excellent agreement with the predicted response. This filter represents one of the highest passive component performances ever reported for ceramic-based MCM technology and highly suitable to incorporate in RF module for cost-effective and compact microwave and mm-wave SOP applications.

Microwave and Optical Technology Letters, 2003

Careful design of via transitions intended for use in practical microwave applications is needed to realize the advantages of lowtemperature co-fired ceramic (LTCC), such as highly integrated buried passive circuits. Grounded coplanar waveguide (GCPW) to asymmetrical stripline vertical interconnects is optimized for thick LTCC substrate. The focus is to develop a vertical transition through thick substrate supporting deep embedded interconnects (DEI). The measured results demonstrate vertical transitions with good performance up to 20 GHz. Embedded LTCC bandpass filter with such vertical transition has been demonstrated with an insertion loss of 2.2 dB and return loss better than Ϫ20 dB at 16.

Microwave and Optical Technology Letters, 2008

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. 5. CONCLUSION As 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.