The basic concept and features are presented of double-sided microwave integrated circuits (double-sided MICs), which effectively utilize various kinds of transmission lines on both sides of a substrate. The fundamental circuits such as 180 degrees hybrids (magic Ts) and many application circuits described here are very useful in developing microwave and millimeter-wave band equipment. The concept of the double-sided MIC technique is also suitable for application to monolithic MICs. >

Double-sided MICs and their applications

A class of novel millimetric uniplanar series resonators are presented, which can be used in monolithic and hybrid uniplanar microwave integrated circuits (MIC's). The proposed structures are able to demonstrate low radiation and compactness characteristics, which are attractive for passive and active monolithic and hybrid integrated circuits. A principle of achieving these high-quality circuits is described and also confirmed by experimental and theoretical results, which are in good agreement up to 50 GHz. To illustrate the features of the proposed series resonators and demonstrate their effectiveness, two classes of miniature coplanar waveguide (CPW) filters (namely, low-pass and bandpass) are designed using these resonators. The developed low-pass filter has some important advantages such as low insertion loss in passband, very wide stopband, high cutoff rates, small size, low number of elements, and an effective control of spurious signals. On the other hand, the newly developed bandpass filter provides an alternative, yet compact, structure to classical filters. Obviously, many other classes of filters or passive components can also be designed.

https://www.just.edu.jo/%7Enihad/files/pap/23.pdf

A class of novel uniplanar series resonators and their implementation in original applications

Novel microwave integrated circuit (MIC) 180/spl deg/ hybrids (magic-T's) suitable for MIC are described. They make use of the two orthogonal modes (even and odd) of the coupled slot lines, and, therefore, have special port location, which is quite different from that of the conventional 180/spl deg/ hybrids such as a rat-race. That is, the two-ports, which correspond to the E-arm and the H-arm of the well-known waveguide magic-T, can be located on the same side, opposite to the other two ports. This feature is of a great practical advantage when applied to an MIC, because the crossing of the transmission lines can be omitted when this type of magic-T is applied to balanced-type circuits such as balanced mixers. Satisfactory experimental results at a center frecuency of 6 GHz are given. The isolation between the E- and the H-ports is better than 30 dB over an octave band, and the frequency sensitivity of the coupling is almost flat in the frequency range from 2 to 10 GHz.

A New MIC Magic-T Using Coupled Slot Lines

Regenerative frequency halvers using double-balanced mixers are analyzed in terms of modified Bessel functions. Particular attention is given to a regenerative divide using a zero-memory double-balanced Schottky diode mixer. Closed-form solutions predict the threshold of turn on, the steady-state input-output amplitude relationship, and the operational bandwidth. Experimental results are also presented. >

Theory of regenerative frequency dividers using double-balanced mixers

New microwave integrated circuit (MIC) power dividers have been proposed. These power dividers utilize both substrate surfaces and employ coupled microstrip-slot lines, microstrip lines, and slotlines; therefore, we make use of the two-sided MIC technique. The out-of-phase-type power dividers, as well as the in-phase-type circuits, can be constructed by the circuit configuration method described in this paper. Coupled microstrip slot lines, an important component of the power dividers, have been analyzed by the spectral-domain method, and their characteristics have been calculated and the numerical results shown for several different structural parameters for the purpose of designing power dividers. The out-of-phase-type power divider was fabricated at the 26-GHz band and good performance achieved, confirming the calculated accuracy through experimental results. The new two-sided MIC power dividers are expected to have wide applications at the millimeter-wave band.

New MIC Power Dividers Using Coupled Microstrip-Slot Lines: Two-Sided MIC Power Dividers

A novel microwave integrated circuit (MIC) double-balanced mixer with good isolation between the three ports is described. The mixer is fabricated using a combination of microstrip lines, slotlines, and coupled slotlines, together with four beam-lead Schottky-barrier diodes. The K-band magic-T has been developed for the double-balanced mixer. The minimum conversion loss measured at a signal frecuency of 19.6 GHz is 4.7 dB. Isolation between RF and LO ports is greater than 20 dB from 18 to 21 GHz. The mixer can be expected to have wide applications in MIC receivers and transmitters up to the millimeter-wave band.

K. Morita

Papers

K-Band Integrated Double-Balanced Mixer