Edan Dalton

Crosstalk between finite ground coplanar waveguides over polyimide layers for 3-D MMICs on Si substrates

Finite-ground coplanar (FGC) waveguide lines on top of polyimide layers are frequently used to construct three-dimensional Si-SiGe monolithic microwave/millimeter-wave integrated circuits on silicon substrates. Requirements for high-density, low-cost, and compact RF front ends on silicon can lead, however, to high crosstalk between FGC lines and overall circuit performance degradation. This paper presents theoretical and experimental results and associated design guidelines for FGC line coupling on both highand low-resistivity silicon wafers with a polyimide overlay. It is shown that a gap as small as 6 /spl mu/m between two adjacent FGC lines can reduce crosstalk by at least 10 dB, that the nature of the coupling mechanism is not the same as with microstrip lines on polyimide layers, and that the coupling is not dependent on the Si resistivity. With careful layout design, isolation values of better than -30 dB can be achieved up to very high frequencies (50 GHz).

Coupling between microstrip lines with finite width ground plane embedded in thin-film circuits

Three-dimensional (3-D) interconnects built upon multiple layers of polyimide are required for constructing 3-D circuits on CMOS (low resistivity) Si wafers, GaAs, and ceramic substrates. Thin-film microstrip lines (TFMS) with finite-width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS fines are susceptible to high levels of coupling, which degrades the circuit performance. In this paper, finite-difference time domain (FDTD) analysis and experimental measurements are used to demonstrate that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions. Furthermore, it is shown that coupled microstrip lines establish a slotline type mode between the two ground planes and a dielectric waveguide type mode, and that the connected via holes recommended here eliminate these two modes.

Coupling between microstrip lines with finite width ground plane embedded in polyimide layers for 3D-MMICs on Si

Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimeter-wave integrated circuits on CMOS (low resistivity) Si wafers. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements are used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions.

A high efficiency 0.25 /spl mu/m CMOS PA with LTCC multi-layer high-Q integrated passives for 2.4 GHz ISM band

We present the first high efficiency CMOS power amplifier utilizing fully integrated multi-layer Low Temperature Co-fired Ceramic (LTCC) high-Q passives for 2.4 GHz ISM band applications. The inductor and capacitor library was built in a multi-layer LTCC board using a compact topology. An inductor Q-factor as high as 110 with a self-resonant-frequency (SRF) as high as 12 GHz was demonstrated. Measured results of the CMOS-LTCC PA show 45% power added efficiency, 23 dBm output power and 18 dB gain at 2.4 GHz with a low 2.5 V drain supply voltage. This result is the first significant step toward a compact transceiver module development utilizing fully integrated multi-layer LTCC high-Q passives and a deep submicron (0.25 /spl mu/m) CMOS technology.

Measured Propagation Characteristics of Finite Ground Coplanar Waveguide on Silicon with a Thick Polyimide Interface Layer

Measured propagation characteristics of Finite Ground Coplanar (FGC) waveguide on silicon substrates with resistivities spanning 3 orders of magnitude (0.1 to 15.6 Ohm cm) and a 20 ¿m thick polyimide interface layer are presented as a function of the FGC geometry. Results show that there is an optimum FGC geometry for minimum loss, and silicon with a resistivity of 0.1 Ohm cm has greater loss than substrates with higher and lower resistivity. Lastly, substrates with a resistivity of 10 Ohm cm or greater have acceptable loss characteristics.

Design and optimization of silicon-based patch antennas using time-domain techniques

The simulated results of a silicon-based microstrip patch antenna are presented. The antenna structure includes an additional layer of low permittivity material sandwiched between the antenna and the silicon substrate. The simulations are performed using two in-house computer codes that make use of the multi-resolution time domain (MRTD) and the finite difference time domain (FDTD) methods to solve for the electromagnetic fields. These techniques are used for the modeling and optimization of various silicon-based antennas.

A hybrid FDTD/quasistatic technique for the accurate modeling of complex integrated structures including effects of lossy metals

This paper presents a method of coupling a quasistatic field solver with the finite-difference time-domain method for the more efficient modeling of multilayer packaging structures including metal and dielectric loss effects. Lossy metal characteristics are first simulated with a dense quasistatic grid and the resulting field correction factors are then used to enhance the accuracy of a much coarser FDTD mesh.

A hybrid FDTD/quasistatic technique including effects of lossy metals

This paper presents a method of coupling a quasistatic field solver with the finite-difference time-domain method for the more efficient modelling of multilayer packaging structures including metal and dielectric loss effects. Lossy metal characteristics are first simulated with a dense quasistatic grid and the resulting field correction factors are then used to enhance the accuracy of a much coarser FDTD mesh.

Accurate modeling of multilayer packaging structures with a hybrid FDTD method

This paper presents a method of coupling a static electromagnetic field solver with the fmite-difference timedomain method for the more efficient modeling of multilayer packaging Structures. Lossy metal characteristics are fxst simulated with a dense static grid and the resulting field correction factors are then used to enhance the accuracy of a much coarser FDTD mesh.