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In this paper, an adaptive N-path filter design technique is presented. The filter designed by this method can be reconfigured to different shapes, e.g., Butterworth or Chebyshev with variable bandwidth (BW), based on the user requirements. In addition, an analytical synthesis procedure is introduced to realize high-order bandpass filters (BPFs) based on N-path architecture with a prescribed set of specifications. A proof-of-concept BPF is fabricated and measured in a 65-nm CMOS process. The filter can be reconfigured to realize different filter shapes by changing coupling capacitors. The BW of the proposed filter is also tunable. The passband of the filter is tunable from 0.2 to 1.2 GHz with a gain of 14.5-18 dB, a noise figure of 3.7-5.5 dB, and a total power consumption of 37.5-52.7 mW. The channel BW can be varied from 20 to 40 MHz and the filter out-of-band third-order intercept point (Δ f=50 MHz) is 25 dBm.

A very low-loss tunable evanescent-mode cavity bandpass filter (BPF) with one-octave (6-12 GHz) tuning range is presented. To implement a very low-insertion loss with wideband operation, a new coaxial-feed structure is devised in the tunable BPF. Across the entire tuning range, the achieved insertion loss is less than 0.5 dB. The 3-dB fractional bandwidth varies from 6.1% at 6 GHz to 12% at 12 GHz. The tenability is realized using silicon microelectromechanical systems diaphragms with slits that are electrostatically actuated. Direct comparison between a solid diaphragm and the proposed stress-reduced diaphragm with slits is presented. The bulk of the filter is realized using physical machining of a tall printed circuit board. This article shows the upper frequency limit that is feasible using milling.

Randomly dispersed particles in a material can be forced to align due to the presence of an externally applied field. These self-aligning materials are examples through which order is obtained through structure created internally which alters the bulk properties of the material. One such material is a magnetically aligned anisotropic conductive adhesive which uses the alignment of ferromagnetic particles in order to create current flow in only one direction. This paper discusses microwave application of such a material. We demonstrate that the magnetically aligned Z-axis anisotropic conductive adhesive works at microwave frequencies interconnecting silicon substrates through 90 GHz. The Z-axis material is found to be a suitable replacement for solder bumping even at high frequencies of operation. The effect of material composition and the radio frequency design is discussed in this paper. Finally, the Z-axis anisotropic conductive adhesive is found to be a suitable cost-effective replacement for solder bumps at high frequencies. Index Terms--Anisotropic media, conductive particles, coplanar waveguides, flip-chip bonding, high frequency, interconnects, packaging.

A 10-GHz filter/receiver module is implemented in a novel 3-D integration technique suitable for RF and microwave circuits. The receiver designed and fabricated in a commercial 0.18-[micro]m CMOS process is integrated with embedded passive components fabricated on a high-resistivity Si substrate using a recently developed self-aligned wafer-level integration technology. Integration with the filter is achieved through bonding a high-Q evanescent-mode cavity filter onto the silicon wafer using screen printable conductive epoxy. With adjustment of the input matching of the receiver integrated circuit by the embedded passives fabricated on the Si substrate, the return loss, conversion gain, and noise figure of the front-end receiver are improved. At RF frequency of 10.3 GHz and with an IF frequency of 50 MHz, the integrated front-end system achieves a conversion gain of 19 dB, and an overall noise figure of 10 dB. A fully integrated filter/receiver on an Si substrate that operates at microwave frequencies is demonstrated. Index Terms--CMOS RF front-end, embedded passives, evanescent-mode cavity filter, heterogeneous integration, packaging, receiver.

The effects of various parameters on the quality of the functional thin metal films, which are fabricated using simultaneous laser sintering and patterning processes are studied. The technique of laser heating can be also used to obtain the desired thermal conditions.