Multi-band RF and mm-wave design solutions for integrated RF functions in liquid crystal polymer system-on-package technology

Abstract

Electronic packaging evolution involves systems, technology and material considerations. In this paper, we present a liquid crystal polymer (LCP) based multilayer packaging technology that is rapidly emerging as an ideal platform for low cost, multi-band and reconfigurable RF front-end module integration. LCP's very low water absorption (0.04%), low cost and high electrical performance makes it very appealing for RF applications. Here we describe main characteristics and real performance of LCP substrate, by means of several design examples. A Single-Input-SingleOutput (SISO) dual-band filter operating at ISM 2.4-2.5 GHz and UNII 5.15-5.85 GHz frequency bands, a dual polarization, dual frequency 2x1 antenna operating at 14 and 35 GHz, and a WLAN IEEE 802.11a compliant compact module (volume of 75x35x0.2 mm 3 ) have been fabricated on LCP substrate, showing the great potential of the System-OnPackage approach for 3D compact, multi-band and reconfigurable integrated RF and millimeter waves functions and modules. IntroductionMiniaturization, portability, cost and performance have been the driving force for the evolution of packaging and system-on-package (SOP) approach in RF, microwave and millimeter wave applications. Recent research shows SOP to be a more feasible and low cost solution than system-on-chip (SOC) approach [1]. Cost, electrical performance, integration density, and packaging compatibility are variables that are often at odds with each other in RF designs. Few material technologies are able address these considerations simultaneously. LTCC is a technology that has excellent electrical performance, dense multilayer integration, and good barrier properties, but it is relatively expensive compared to standard FR4. Most other substrate and packaging materials do not have low enough water absorption properties in tandem with multilayer construction capabilities to be considered for vertically integrated designs. Liquid crystal polymer (LCP) provides the all-in-one solution for such integration approach in terms of high quality dielectric for high performance multiband passive design, excellent substrate for heterogeneous SOP integration as well as for MEMS structures, enabling the implementation of multiband and reconfigurable modules.In this paper, we present the potential of LCP as the substrate as well as the packaging material for wireless applications. In the following sections, the LCP fabrication

3D Multilayer Integration and Packaging on Organic/Paper Low-cost Substrates for RF and Wireless Applications

“…The presented Single-Input Single-Output (SISO) Dual band filter takes advantage of LCP's stable-with-frequency electrical characteristics to operate at two different frequencies with antennas in the UWB band. The SISO dual band filter uses the "dual behavior resonator" technique to operate at the WLAN operating frequency bands, ISM 2.4 GHz and UNII 5 GHz [2]. The dual behavior resonance technique is achieved through the use of two optimized open-ended stub resonators.…”

Liquid Crystal Polymer (LCP): The ultimate solution for low-cost RF flexible electronics and antennas

“…The presented Single-Input Single-Output (SISO) Dual band filter takes advantage of LCP's stable-with-frequency electrical characteristics to operate at two different frequencies with antennas in the UWB band. The SISO dual band filter uses the "dual behavior resonator" technique to operate at the WLAN operating frequency bands, ISM 2.4 GHz and UNII 5 GHz [3]. These bands have been targeted because of the ever growing number of services allocated in this part of the spectrum, including Bluetooth, IEEE 802.11a/b/g, and the introduction of dual-band wireless systems [3].…”

“…The SISO dual band filter uses the "dual behavior resonator" technique to operate at the WLAN operating frequency bands, ISM 2.4 GHz and UNII 5 GHz [3]. These bands have been targeted because of the ever growing number of services allocated in this part of the spectrum, including Bluetooth, IEEE 802.11a/b/g, and the introduction of dual-band wireless systems [3]. The dual behavior resonance technique is achieved through the use of 2 optimized open-ended stub resonators.…”

“…The insertion loss and return loss at the central frequency are 2.4dB and 15dB for the 2.4 GHz band, respectively, and 1.8dB and 10dB for the 5 GHz band, respectively. It exhibits also an out-of-band rejection as high as 45 dB between the L and C band [3].…”

Liquid Crystal-Based Reconfigurable Tunable Filter with DBR Topology

“…This paper propose device using planar technology-based on LC materials. This choice allows the LC anisotropy property to the excited radio frequency field [12,13] polarization with an electrostatic field. Numerical results for design filter with an LC cavity are compared with the existing data to confirm the accuracy of the proposed analysis.…”