S.-W. Yoon

Very high-Q inductors using RF-MEMS technology for System-On-Package wireless communication integrated module

We present the fabrication and the characterization of very high-Q suspended RF-MEMS inductors for RF applications in C-band, X-band and Ku-band. The fabrication technique relies on conventional MEMS micro-machining on a low cost ceramic RF substrate. This low temperature, low cost manufacturing technique is therefore compatible with the fabrication of a complete S-O-P wireless integrated module. A physical based model of the inductors is presented. It takes into account the influence of substrate losses and radiation losses. The fabricated devices exhibit very high performances such as Q above 100 and self-resonance frequency as high as 50 GHz.

Liquid crystal polymer-based integrated passive development for RF applications

A Liquid Crystal Polymer (LCP) based multilayer packaging process is presented for RF/microwave applications. LCP is gaining increasing interest as a choice technology in the packaging community due to its superior thermal and electrical properties including low loss, low dielectric constant and low CTE characteristics. For the first time, we present a thorough study of the design, model, and measurement of integrated passives using LCP. A coplanar waveguide transmission line test structure demonstrates an insertion loss of 0.35 dB at 23 GHz and a return loss better than 15 dB to 30 GHz. Quality factors (Q) in excess of 70 and a self resonance frequency (SRF) to 29 GHz have been achieved. A bandpass filter implementation is also demonstrated to realize a c band module. Advantages of passive integration using built up LCPs as opposed to multilayer organics are discussed.

Active-inductor-based low-power broadband harmonic VCO in SiGe technology for wideband and multi-standard applications

This paper presents the first reported description, analysis, and measured performance of a wideband harmonic generation technique that utilizes the non-linearity of a tunable active inductor (TAI) in SiGe technology. The technique demonstrates the highest reported measured fundamental tuning range of 3.5 GHz, for a TAI-VCO, from 1.7-5.2 GHz (100% tuning) while consuming only 3.7 mW from a 1.8 V supply. Higher frequencies, as high as the 4th harmonics, between 3.4-8.4 GHz, are generated with output power close to or higher than that of the fundamental frequency. Detailed analysis has been performed to optimize the noise performance of the TAI, as well as to study the principle of harmonic generation.

RF-microwave multi-band design solutions for multilayer organic system on package integrated passives

We present multi-band design solutions for integrated passives using multilayer organic (MLO) process technology for RF and microwave System on Package (SOP) module development. The components developed in this technology include embedded high-Q compact inductors and filters designed in three frequency bands: S, C and Ku applicable for Bluetooth, MMDS, IEEE802.11a WLAN and satellite communications. Measured inductor Q-factor as high as 182 and Self-Resonant-Frequency (SRF) as high as 20 GHz, which represents the highest Q in its frequency range reported to date in a multilayer technology, have been demonstrated. A time domain electromagnetic modeling technique is also use to characterize the passive devices.

Integrated inductors in the chip-to-board interconnect layer fabricated using solderless electroplating bonding

Integrated inductors are typically formed either on-chip or embedded in the chip package or board. In this work, we explore the possibility of forming inductors in the chip-to-board interconnect layer. The solderless technique of electroplating bonding is used to simultaneously form inductor structures as well as chip-to-board interconnect The use of the gap between the chip and substrate for inductors not only increases integration density, but also allows large magnetic cross-sectional areas to be achieved. To demonstrate the technology, 3- and 7-turn inductors 500 /spl mu/m in height were fabricated. These inductors showed inductance values of 3.45 nH and 10.5 nH, respectively. The measured Q-factors of the 3- and 7-turn inductors were 70 and 55 respectively, which agreed very well with modeling results.

A 0.35-/spl mu/m CMOS 2-GHz VCO in wafer-level package

This letter presents a complementary metal oxide semiconductor (CMOS) voltage-controlled oscillator (VCO) with a high-Q inductor in a wafer-level package for the LC-resonator. The on-chip inductor is implemented using the redistribution metal layer of the wafer-level package (WLP), and therefore it is called a WLP inductor. Using the thick passivation and copper metallization, the WLP inductor has high quality-factor (Q-factor). A 2-nH inductor exhibits a Q-factor of 8 at 2 GHz. The center frequency of the VCO is 2.16 GHz with a tuning range of 385 MHz (18%). The minimum phase noise is measured to be -120.2 dBc/Hz at an offset frequency of 600 kHz. The dc power consumed by the VCO-core is 1.87 mW with a supply voltage of 1.7 V and a current of 1.1 mA. The output power with a 50-/spl Omega/ load is -12.5/spl plusmn/1.3 dBm throughout the whole tuning range. From the best of our knowledge, compared with recently published 2-GHz-band 0.35 /spl mu/m CMOS VCOs in the literature, the VCO in this work shows the lowest power consumption and the best figure-of-merit.

Embedded IC and high-Q passives technology for ultra-compact Ku-band VCO module

In this letter, we present a novel ultra-compact embedded IC integration approach for system-on-package (SOP) based solutions for RF and wireless communication applications. This concept is applied to the integration of a Ku band VCO module. The module fabrication is described and the impact of the packaging on the chip-set performances is discussed. The final thickness of the module is about 150 /spl mu/m. The embedded VCO exhibits an oscillation frequency of 15.4 GHz, a phase noise of -99.2 dBc/Hz at a 1 MHz offset and maximum output power of 10.67 dBm. Multilayer interconnects built with modified MCM-D technology using advanced photosensitive epoxy Intervia 8000 is described. Characterization and modeling of RF inductors are detailed and show quality factor as high as 80 at 10 GHz.

C-band oscillator using high-Q inductors embedded in multi-layer organic packaging

We present C-band oscillators with external high-Q inductors: wire-bond inductors and embedded inductors in a Multi-Layer Organic (MLO) board fabricated by a thick-film MCM-L technology. The phase-noise performance of oscillators is compared with the oscillator using on-chip inductors. Inductors are designed to obtain high quality factor in C-band. The phase-noise performance of the oscillator with on-chip inductors measures -108 dBc/Hz at 600 kHz offset frequency, and that of the oscillator with external inductors shows -113 dBc/Hz at the same offset. Using MLO inductors, the phase-noise is better than the oscillator with on-chip inductors and comparable to the oscillator with wire-bond inductors. To our knowledge, this is the first C-band oscillator using inductors embedded in the multi-layer organic packaging technology. This is also the first report comparing the performance of oscillators using three different inductor technologies: on-chip integration, wire-bonding, and multi-layer organic packaging technology.

Novel combiner for hybrid digital/RF fiber-optic application

In this paper, a combiner for a hybrid digital/RF fiber-optic link system is designed and implemented via the multi-layer organic (MLO) process. This combiner aggregates the baseband signal (7 Gbit/s PRBS) with the modulated RF signal (14 GHz) through the vertical coupling structure. The insertion loss between the RF port and output port of the combiner is measured as 1.9 dB. Measurement results also show isolation greater than 10 dB at 7 GHz and 38 dB at 14 GHz between the baseband port and RF port. This new type of combiner can work as a key component in hybrid fiber-optic applications.

Investigation of inductors for digital Si-CMOS technologies

This paper investigates the performance of passive and active inductors for digital Si-CMOS technologies. The extreme low-resistivity of the Si-substrate and the absence of thick top metal layers in digital-CMOS processes prevent the implementation of high-Q passive inductors, and demand alternate solutions. A detailed comparison between the active and passive inductors based on several performance criteria such as Q-factor, area, tunability, noise, linearity, EMI, floor-planning etc reveals the tremendous potential of the high-Q tunable active inductors. An optimization guideline for the grounded-inductor topology has also been suggested. As a basis of comparison, oscillators have been implemented using both the inductors. The active inductor VCO achieves a much higher tuning range and occupies a much smaller die-area than the passive implementation at the cost of degraded phase-noise performance