Philip Pieters

Integration of passive components for microwave filters in MCM-D

The increasing demand for high density packaging technologies and the evolution to mixed digital and analogue devices has been the on-set of increasing research in microwave thin film multi-layer technologies such as the MCM-D technology. In this technology passive components may be integrated in the substrate and combined to realise more complex microwave functions. In this paper a basic comparison and a process parameter sensitivity analysis is made for the transmission line characteristics of interconnections in single layer MIC technology and in thin film MCM technology. For reasons of better accessibility, enhanced phase velocity and reduced process tolerance susceptibility, coplanar lines on MCM show to be advantageous. However, the multi-layered nature offers alternative possibilities to implement passive components. In this way a coplanar floating patch capacitor is introduced. Other passive components, such as thin film NiCr resistors, high quality spiral and line inductors and other types of capacitors are discussed. These passives have been combined to realise integrated passive filter functions, of which an example is shown.

Chip-package co-design of a 5 GHz RF front-end for WLAN

Single-package integration of complete transceivers based on a thin-film MCM technology (MCM-D) with integrated passives is demonstrated with a 6.7/spl times/6.5 mm/sup 2/ single-package front-end. This front-end includes the RF blocks and two RF bandpass filters of a 5 GHz WLAN receiver.

Integrated microwave filters in MCM-D

Thin film multilayer Multichip Module technology (MCM-D) may be used to realise microwave circuits such as capacitors and inductors. These may be combined to form passive filter structures. Such filters are an essential element of microwave circuits. On monolithic microwave integrated circuits, these structures require a large area resulting in a high cost. In this paper we present microwave filters integrated in multilayer MCM-D technology. As MCM-D also provides the interconnect between the individual microwave components, an integrated microwave Junction is realised, reducing the global system cost. The inductive and capacitive elements that are used to realise the filters are presented. The design of a low pass and a band pass filter using these elements is discussed. Finally, measurements of realised filters are presented.

Spiral inductors integrated in MCM-D using the design space concept

High quality integrated spiral inductors are essential components of integrated microwave applications such as passive filters. In order to be able to determine the specific inductor geometry that provides the highest possible quality factor for a given inductance value and frequency behaviour, the concept of inductor design spaces is introduced. These design spaces link inductor quality factors with inductance values and frequency ranges. Using a new theoretical inductor model that allows the prediction of the behaviour of any coplanar multi-turn circular spiral inductor on a thin film multilayer MCM-D structure, the design spaces may be explored for the geometries that produce the highest quality factors. The paper describes both the calculation of the inductor model and the use of the design space concept. Finally, the application of this concept for the design of passive filters is indicated.

Generalized analysis of coupled lines in multilayer microwave MCM-D technology-application: integrated coplanar Lange couplers

In this paper, the design and realization of coplanar Lange couplers integrated in a multilayer thin-film multichip module deposition (MCM-D) technology is discussed. The MCM-D technology has been well established for the interconnection of high-speed digital circuits, and is now being recognized to be very useful for the integration and interconnection of microwave components. In this way, passive structures, such as spiral inductors, filters, and couplers, may be realized efficiently and more cost effective in MCM-D compared to monolithic microwave integrated circuits. The presented coplanar Lange couplers have been designed using an equivalent coupled-line model. A general and computationally efficient method for the determination of the required modal characteristic impedances and the related geometrical parameters in a microwave multilayer coupled-line topology is presented. Also, a way to calculate the optimum coupled line length is given. Using the described method, coplanar Lange couplers have been realized and then measured. Comparison between the measurement results and HP Momentum simulations show good agreement and indicate the feasibility of designing and integrating such components in MCM-D.

High-Q integrated spiral inductors for high performance wireless front-end systems

Inductors are essential components in wireless front-end systems. In this paper we present high-Q spiral inductors integrated in thin film multilayer MCM-D technology with quality factors of more than 100 at microwave frequencies. These inductors, together with other integrated passive components such as capacitors, resistors and interconnections are used to realize high performance systems for wireless front-ends. Examples of fully integrated filters, couplers, a DECT VCO and a LNA for 5.2 GHz wireless LAN applications are discussed.

Suppression of the parasitic modes in CPW discontinuities using MCM-D technology-application to a novel 3-dB power splitter

In this paper, a new method for the suppression of the parasitic modes in the coplanar waveguide (CPW)-based microwave circuits is presented. The proposed method replaces the costly and mechanically unstable air-bridges, It uses tunnels (bridges) running below (above) the CPW and isolated from it using a thin film layer. This method is convenient for MCM-D technology in which thin films are deposited over the substrate to support the required interconnects. The method is applied to the band reject filter presented in an earlier paper by Rittweger et al. (1991) and compared with the case of air-bridges. The effects of the tunnel parameters on the filter performance are presented and discussed. The new suppression mechanism is also applied on a novel 3-dB power splitter. Experimental and theoretical results of the new power splitter are presented and compared. The agreement between theory and measurements ensures the efficiency of the proposed suppression mechanism.

Integration of passive components in thin film multilayer MCM-D technology for wireless front-end applications

In the current trend towards portable applications, the integration of passive components has become very important. This paper introduces high quality integrated passive components in thin film multilayer MCM-D technology. The main characteristics and modeling issues for use at RF and microwave frequencies are discussed. Also, a number of circuits applicable in wireless front-ends using the integrated passives are presented. These show that MCM-D may be used for the integration of miniature systems for wireless applications.

Advances in microwave MCM‐D technology

The thin film multilayer multichip module technology (MCM‐D) was originally used for the interconnection of high speed digital circuits in a single module. Nowadays, the technology is more and more evolving towards use in the interconnection of RF and microwave circuits with integrated passive components. This paper gives an overview of this evolution towards microwave MCM‐D technology and the recent advances with respect to the integration of high quality passive components. With a discussion on the flip chip mounting of active devices, the link towards fully integrated high frequency front‐end systems is pointed out.

MCM-D technology for integrated passives components

Integrated passive components are becoming of growing importance for new telecommunication circuits. In this paper, a thin film multilayer MCM-D technology for the integration of almost any type of passive structure is presented. The capabilities of the technology are demonstrated up to microwave frequencies through the examples of various realized integrated passive components.