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Microfluidically repositionable selectively metallized plates (SMPs) are utilized for the first time to design and realize microstrip line combline filters with wide frequency tuning and high power-handling capability. A continuous frequency tuning range of 2.7:1 is achieved by utilizing tight coupling between the SMP and open-ended microstrip line resonators in order to change their length for tuning from 2.5 to 4 GHz and capacitively load one of their open ends for tuning from 1.5 to 2.5 GHz. The unloaded quality factor (Qu) of the resonators is maintained relatively constant (210–190) across the entire tuning range allowing for the low insertion loss (IL) and high power-handling capability. Specifically, a ~5% constant fractional bandwidth fourth-order filter design is discussed and experimentally verified. The filter exhibits less than 3-dB IL across the 2.7:1 tuning range. It is shown that the filter’s power handling capability can reach up to 15 W under constant average power excitation. [ABSTRACT FROM PUBLISHER]

In this paper, a new family of low-profile high quality factor cavity resonators, termed distributed resonators, is introduced. Initially, the theory of operation of the proposed distributed resonator is presented regarding two, three, and four coupled resonator elements. Based on this, a further-improved arrangement of resonator elements is proposed. It is shown that the height of the individual resonator can be controlled by the number of resonant elements and can be almost arbitrarily low. As an experimental verification, a three-pole filter operating at 1800 MHz with a bandwidth of 40 MHz is designed and fabricated. The individual resonator of this filter comprises 25 individual resonant elements, with an overall cavity height of 7 mm, or 15°, and an unloaded quality factor of 1900. The height of the presented filter is significantly lower than any other air-filled filter cavity solution available in the literature. The measured insertion loss of the filter is 0.5 dB, which is in excellent agreement with the theoretically predicted value of 0.4 dB. [ABSTRACT FROM PUBLISHER]

This paper presents the detailed design, fabrication, and measurement of cavity resonators and filters for silicon (Si)-based millimeter-wave integrated circuits. The design of the cavity resonators and filters is conducted using Ansoft High Frequency Structure Simulator. The cavity resonators and filters are fabricated on a 4-in Si substrate using the air-gapped microcoax technology, which is based on a multilayer low-temperature copper Damascene process. The fabricated cavity resonators have measured unloaded quality ( Qu ) values of 666 and 864 for 36 and 60 GHz, respectively. Two-pole bandpass cavity filters have achieved an insertion loss close to 0 dB and a return loss better than 20 dB for both 36- and 60-GHz passbands. The cavity resonator and filter have simple structures and avoided excessive global optimization for the design. Hence, the accuracy, time, and complexity of the design can be improved significantly. The fabrication technology demonstrates the advantages of ultralow loss and dispersion, perfect impedance matching, pure transverse electromagnetic propagation mode, and ultrahigh isolation and power-handling capability. Furthermore, the process has a low thermal budget and is fully compatible with CMOS back-end-of-line (BEOL) process, which can be integrated with other air-gapped microcoaxial components to realize a high-performance microwave system on chip. [ABSTRACT FROM PUBLISHER]

The antenna factor (AF) above the ground plane changes with respect to the height and obtaining a height pattern of the AF with a sufficient resolution is time consuming. In this paper, a novel method is proposed to obtain an accurate AF at an arbitrary height by a single site insertion loss (SIL) measurement. A ratio of the E-field strength at the location of the antenna under calibration (AUC) to the current amplitude at the transmitting antenna port is introduced. By using this ratio, the AF of the AUC at the height can be obtained by only one SIL measurement. Unlike the conventional method, the multiple SIL measurements are no longer necessary and the proposed method remarkably reduces the measurement time. By using the AFs properly calibrated by the proposed method, the effects of antenna characteristics are significantly reduced in the normalized site attenuation measurement. [ABSTRACT FROM PUBLISHER]