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In this paper, a new design concept of Schiffman phase shifters under the operation of the second phase period in frequency domain is presented and analyzed. By investigating phase properties of the C-section structure, we first find that its second phase period is another independent and distinctive working region for Schiffman phase shifter, in addition to its first phase period. In contrast to traditional counterparts working on the first phase period, which are suitable for small phase shift from 0° to 90°, the Schiffman phase shifters on the second phase period are suitable for the large phase shift from 90° to 180°. It is because of the opposite phase variation property that the electrical length of reference line gets shortened as the phase shift value increases. Compared with the first phase period, the second phase period can achieve wider phase shift bandwidth under the same coupling degree. This feature is believed to be very useful in the limited realizable coupling degree cases. In this context, the closed-form synthesis formulas of Schiffman phase shifter on the second phase period are presented. Meanwhile, detail theoretical analysis of the phase shift bandwidth and phase deviation is carried out. In final, two Schiffman phase shifters on the first and second phase periods are designed and fabricated to validate our proposed concept and approach in the experiment. [ABSTRACT FROM AUTHOR]

This paper addresses the miniaturization of microwave vector network analyzers (VNAs) and the future vision of the VNA on a chip. Therefore, a highly integrated two-port VNA with a multioctave bandwidth from 4 to 32 GHz is presented. The proposed system is based on a fully integrated radio-frequency frontend consisting of a two-port stimulus, a four-channel heterodyne receiver, and a wideband testset. The testset is comprised of on-chip multisection directional couplers. The chip is operated inside a hardware demonstrator using a 16-term calibration procedure. The measurement of arbitrary devices under test is in excellent agreement with commercial measurement equipment and showed a mean deviation from the reference measurement of 0.17 dB and 1.29° regarding the forward transmission of a coaxial 30-dB attenuator. The system and receiver dynamic ranges are 44–77 and 82–101 dB at a resolution bandwidth of 100 kHz over the full system bandwidth. The measurements are highly repeatable and are robust against drift over time. As a proof of concept, the developed integrated network analyzers are utilized in a biomedical sensing scenario with an external and an on-chip sensor. Both approaches showed good sensitivity regarding the mixture ratio of binary solutions of ethanol and methanol. [ABSTRACT FROM PUBLISHER]

This paper presents a highly symmetric 1\! :\! n concentric vortical transformer (CVT) technology, which can be implemented with slab inductors. The CVT and several widely used planar transformer structures are analyzed to show the characteristic distinction of the CVT. The proposed CVT was developed in an integrated passive device technology along with the popular distributed active transformer (DAT) for comparison. Under the same real-part impedance transformation ratio at 2.4 GHz, the outer diameter of the CVT is only 48% of the DAT. Moreover, 89.4% transformation efficiency and 191% - \1-dB fractional bandwidth are achieved by the CVT from a high coupling coefficient of 0.9. The symmetric nature of the CVT makes it capable of achieving far less variation than the DAT in resistance and reactance among multiple input ports when used for power combining. [ABSTRACT FROM PUBLISHER]

This paper proposes a novel class of wideband metal cavity multiple-mode bandpass filters (BPFs), consisting of a triple-mode filter and a quadruple-mode filter. Two TE11 degeneration modes in a single metal cavity are excited by using an off-centered approach instead of a traditional corner-cut approach. They work together with the TM10 mode to constitute a three-pole wide passband with a fractional bandwidth of 30% at the central frequency of 3.2 GHz. Moreover, an off-centered metal cylinder can properly excite an extra TM11 mode in the passband. As such, this TM11 mode, TM10 mode, and a pair of degeneration TE11 modes can be simultaneously utilized to form a quadruple-mode BPF. Compared with the triple-mode BPF, the quadruple-mode BPF has better performance in term of the steepness of rejection skirt. The fractional bandwidth of this BPF can achieve up to 31%. In final, the two proposed BPFs are fabricated by using the silver plated aluminum technology. Measured S-parameter frequency response and group delay have satisfactorily matched with the simulated results. [ABSTRACT FROM PUBLISHER]

In the above paper two equivalent circuits of $L_{T}-$ and $\Pi $ -types for a 90° transmission-line section (TL) are suggested only for $N = 1$. However, the design formulas for $N= n$ , where $n\ge 1$ and integer, are already published for $L_{T}$ -types and for $\Pi $ -types [3, Fig. 6(c) with $\Theta _{a}= 0^{\circ }$ ], , and the advantages for $N \ge 2$ are verified for $L_{T}$ -types in and $\Pi $ -types , , as well. [ABSTRACT FROM AUTHOR]

We propose a wideband lumped element directional coupler using lossy negative capacitance (NCAP). NCAP provides a broadband resonance effect combined with passive inductors and capacitors in a circuit, enabling the coupler to exhibit wideband directivity performance. In addition, a 3-dB loss in the NCAP enhanced the bandwidth at the expense of the transmission gain, which decreased by only 0.3 dB. The proposed coupler was implemented in the IBM 7RF 180-nm CMOS technology. The size of the core chip is $1180\,\,\mu \text {m} \times 570\,\,\mu \text{m}$. The designed NCAP provides a capacitance of −13 pF using a supply voltage of 2.7 V and a current of 9.6 mA. The coupling was designed to be −10 dB at the center frequency of 1 GHz. The bandwidth was defined by the frequency range, which exhibited a directivity of more than 30 dB. The S-parameter measurements showed an absolute bandwidth ranging from 0.86 to 1.12 GHz, and a fractional bandwidth of 26%. In the bandwidth, the coupling had a 0.5-dB variation, the transmission loss was smaller than 2.14 dB, and the noise figures were 1.8–2.5 dB. [ABSTRACT FROM AUTHOR]