Compact Circuit Simulation Model for On-Chip Inductor and Transformer for RF Integrated Circuits

Abstract

This paper describes modeling of on-chip inductors using lumped elements [15][16][17]. In this paper, a circuit and transformers for high frequency integrated circuit simulation model for on-chip inductors and transformers has applications. The effects of the substrate losses, substrate been developed. This model can help the designers to predict capacitances, overlap capacitances between the turns of spiral and optimize the device characteristics. It is also useful to and the cross-under layer, and the oxide capacitance between the simulate on-chip inductors and transformers using integrated spiral and the substrate are included in the analysis. Quality factor and scattering matrix forward transmission coefficient are circuits CAD tools such as SPICE. computed based on the proposed model. This model will facilitate This paper is organized as follows. Section II describes onon-chip inductor and transformer design and also useful to chip inductor equivalent circuit and modeling. Modeling of simulate on-chip inductors and transformers using integrated stacked on-chip transformer is presented in Section III. Results circuits CAD tools such as SPICE. and discussions are described in Section IV and it is followed Keywords-on-chip inductor; on-chip transformer; self and by conclusion in Section V. mutual inductances; scattering matrix, qualityfactor. Fig. 1 shows implementation of on-chip spiral inductor. The The demands placed on portable wireless communication inductor is a metal layer grown on a top of Si substrate. The equipments for high performance and integration levels have equivalent lumped model is shown in Fig. 2. The inductance generated much interest in integrated radio frequency (RF) and resistance of a spiral are represented by Ls and Rs inductors and transformers. In earlier days RF passive respectively. Cs is the overlap capacitance between the turns components such as inductor and transformer were of spiral and the cross-under layer. Cox is the oxide implemented as off-chip components. As the increasing of the capacitance between the spiral and the substrate. Csi and Rs, operating frequency, on-chip radio frequency integrated are the parameters modeling substrate losses and capacitive circuits (RFICs) are received a great attention because of the effects respectively. potential of achieving low cost, low supply voltage, low power II. MODELING OF ON-CHIP INDUCTOR I. INTRODUCTIONThe series inductance Ls includes both the self and mutual dissipation, small size, low noise, and high operating inductances and given by frequency [ 1].On-chip inductor is one of the essential elements of Ls = Lsef+ M+-M (1) communication circuit blocks. It is widely used in many where Lseif is the self inductance and for a rectangular applications such as voltage-controlled oscillators, low noise conductor it is a summation of the self-inductances of straight amplifiers, on-chip LC filtering, and mixers [2-6]. On the segments [18] and can be expressed as other hand, on-chip transformer has variety applications on the on-chi...

On-Chip Inductor Technique for Improving LNA Performance Operating at 15 GHz

“…A lumped circuit model of on-chip spiral inductor grown on Si substrate is shown in Figure 2 [9][10][11]. L S and r S are the series inductance and resistance of the spiral respectively.…”

“…The inductance of a spiral is a complex function of its geometry and includes both self and mutual inductances. The expressions for on-chip spiral inductor parameters are given by [9]: …”

A unified analytical and scalable lumped model of RF CMOS spiral inductors based on electromagnetic effects and circuit analysis

“…Analytical extraction techniques based on network analysis [3][4][5] and fitting procedure [14,[20][21][22] have been also investigated, and are more efficient. Indeed, these methods are related to the physical phenomena which occur in spiral inductors.…”

“…Physical and analytical approaches based on simple-p network to model spiral inductors firstly proposed [3][4][5] have been successfully applied to inductors on insulating substrates. Nevertheless, the simple-p model encounters serious problem to describe inductors on conductive substrate, and does not consider proximity effects.…”

“…In the design of analog RFICs, models of spiral inductors are necessary to predict, simulate and optimize the responses of circuits. Several models of spiral inductors have been reported such as the simple-p [3][4][5][6][7], T-models [8,9], double-p [10][11][12][13], and enhanced simple-p [14][15][16][17]. Enhanced simple-p and double-p networks have been introduced to model high parasitic effects such as proximity effects and substrate coupling between the two ports of the spiral.…”