Calibration and adjustments of degree‐1 and ‐2 re‐entrant turnstile circulators using a partially recessed quarter‐wave long dielectric resonator

This paper presents narrowband extracted pole (EP) filters operating in Ku-Band composed out of different types of resonators. The nonresonating nodes (NRNs) and the input/output couplings are realized as waveguides, while all other resonators are realized by TE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01δ</inf> mode dielectric resonators (DRs). The usual disadvantage of increased space requirements due to the additional NRNs needed for EP filters, in comparison with classical filters, is reduced here by the use of TE mode DRs. All DRs are located above the NRNs, which enables the coupling of the different types of resonators as well as a compact design. To validate the mixed design, the proposed filter is manufactured and the measured results are compared with the simulation. Possibilities to extend the design for a flexible positioning of the transmission zeros (TZs) or a higher selectivity are discussed.

This paper presents the design of a hybrid narrowband dual-band bandpass filter with in-band transmission zeros (TZs) in the Ku-band, whose passbands are realized by different types of resonators. The upper passband is realized by waveguide resonators, while the lower one is implemented by TE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01δ</inf> mode dielectric resonators (DRs). The filter synthesis process is based on using frequency transformation. To validate the mixed resonator design, the proposed filter is manufactured and the measurement results are compared with the simulation. The passbands of the manufactured filter are designed for a bandwidth of 40 MHz and center frequencies of 13.47 GHz and 14.05 GHz, respectively.

A new type of dielectric resonator used in millimeter wave band is presented, which is called whispering gallery mode dielectric resonator (WGDR). We also derived a method to calculate its resonant frequency and realized a simple band-stop filter in W-band with leuco sapphire mono-crystal dielectric resonator and rexolite dielectric waveguide. The results show that WGDR has many advantages.

On-chip mm-wave dielectric resonator filters are presented. Low-loss alumina ceramic spheres resonating in a non-radiative mode are used as dielectric resonators. Accurate placement of the resonator spheres is ensured by precise etching of shallow crates in the back-end-of-line low-permittivity dielectric layers atop the semiconductor chip. The spheres are placed in and aligned by these crates. The multi-sphere filter is fed by on-chip microstrip lines. Coupling between microstrip line and sphere can be enhanced by quarter-wave on-chip microstrip resonators. A metallic plate atop the spheres and parallel to the chip holds the spheres in position and prevents radiation. Filters are fabricated on a standard silicon wafer with two metal layers on top, separated by polymer dielectric. Measurements of 3-pole filters at 65 GHz and 95 GHz show an insertion loss of 1.4 dB and 1.0 dB, for a bandwidth at 3 dB insertion loss of 3.5% and 3.9%, respectively.

Full wave modeling of the coupling structure between a double ridge waveguide and dielectric resonator in a rectangular cavity through an iris is presented. Eigen modes of the double ridge waveguide, and the discontinuities of the structures are obtained by rigorous mode matching method. By applying the cascading procedure, the reflection coefficients of the coupling structure can be obtained. From the phase variation of the reflection coefficient and circuit theory, resonant frequency and input/output coupling of the structure are accurately determined. An equivalent circuit model of the resonant structure is established. The computed results are compared with those obtained by other methods and shown to be in good agreement, which verifies the theory.

In this report, a self-packaged millimeter-wave reflectionless bandpass filter based on LCP multilayer suspended microstrip structure is proposed, and a bandpass part combining bandstop part is used to realize the nonreflection characteristic. The reflectionless bandpass filter has a center frequency of 36.3GHz, an insertion loss of 0.94dB, and a return loss with attenuation of more than 12dB in the frequency band of 5GHz-70GHz. In addition, a self-packaged wideband millimeter wave bandpass filter based on LCP multilayer suspended coplanar waveguide (CPW) and dielectric resonator is also proposed, which centers at 49.4GHz with a relative bandwidth of 35.9%, and an insertion loss of 1.4dB.

We report the implementation of the XOR and XNOR logical operations using an electro-optic circuit, which is fabricated by CMOS-compatible process in the silicon-on-insulator (SOI) platform. The circuit consists of two cascaded add-drop microring resonators (MRRs), which are modulated through electric-field-induced carrier depletion in reverse biased pn junctions embedded in the ring waveguides. The resonance wavelength mismatch between the two nominally identical MRRs caused by fabrication errors is compensated by thermal tuning. Simultaneous bitwise XOR and XNOR operations of the two electrical modulating signals at the speed of 12.5 Gb/s are demonstrated. And 20 Gb/s XOR operation at one output port of the circuit is achieved. We explain the phenomena that one half of the resonance regions of the device are much more sensitive to the round-trip phase shift in the ring waveguides than the other half resonance regions. Characteristic graphs with logarithmic phase coordinate are proposed to analyze the sensitivity of the demonstrated circuit, as well as several typical integrated optical structures. It is found that our circuit with arbitrary chosen parameters has similar sensitivity to MRRs under the critical coupling.

This study presents a novel dual-ridged dual-mode dielectric waveguide resonator (DWR) for dual-band bandpass filter (BPF) designs. It employs the fundamental mode quasi-TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">110</sub> and the second resonant mode quasi-TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">120</sub>. Two parallel ridges are placed on the top and bottom surfaces of the DWR at the maximum electric-field areas of the quasi-TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">120</sub> mode to control and reduce its resonant frequency. A metallized nonthrough hole at the DWR’s center controls and decreases the quasi-TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">110</sub> mode’s resonant frequency. Therefore, a very compact volume is achieved for the dual-mode DWR. For verification, a fourth-order dual-band BPF is designed, fabricated, and measured by using the proposed resonator. The measured results highlight its key benefits: miniaturized volume, lightweight, low insertion loss, and flexible control over the center frequencies and bandwidths of both passbands.

In this article, a dual-mode dielectric waveguide resonator (DWR) is proposed. A dual-band bandpass filter (BPF) is fabricated using this DWR. The two passbands are constructed by a pair of higher-order modes. These higher-order modes are the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{TM}_{210}$</tex> mode and the TM120 mode, which are all from the rectangular dielectric waveguide resonator. Therefore, by changing the width of the resonator cw and the length of the resonator cl, the resonant frequencies of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{TM}_{210}$</tex> mode and the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{TM}_{120}$</tex> mode are able to be changed independently. The center frequencies of the filter can be adjusted freely. To excite and extract the modes, metallized blind holes can be set where their electric-fields are the strongest. In this way, the two modes do not affect each other. The coupling structures for different modes are realized by connecting corresponding metallized blind holes. By changing the depth of metallized blind holes at different positions on the resonator, therefore, the coupling coefficients of the two passbands are able to be under control freely so as to adjust the bandwidths of the two passbands independently. At last, the designed BPF's frequencies and bandwidths are able to be controlled freely.

This paper presents a design of dielectric waveguide filter using dual-mode dielectric waveguide resonators (DWRs). The filter is formed by a ceramic monoblock, thus it is compact and ease of fabrication. The employed degenerate modes of DWR are TE101 and TE011 mode, which can be coupled by a slot on the dielectric block. The coupling between a dual-mode DWR and a single-mode DWR is realized by aperture and slot. The external coupling is realized by a silver-coated blind hole that aligns to the mode for excitation. Transmission zero (TZ) can be flexibly generated above or below passband, by changing the relative position of coupling slot. A sixth order bandpass filter working at 4.9 GHz is designed using dual- and single-mode DWRs. The filter is fabricated and measured, agreeing well with simulation. This filter has compact size, low insertion loss, good selectivity and wide spurious-free response, which is applicable to 5G base stations.

The eigenpolarizations and resonant frequencies are derived for a circular dielectric waveguide resonator (EH11 mode) terminated by perfectly reflecting metallic rooftop mirrors. It is demonstrated that, in the far-IR region, circularly polarized helical standing waves result from an arbitrary angular misalignment of the rooftop creases. Further, the right and left circularly polarized modes have different resonant frequencies.

A dielectric waveguide resonator formed by a rectangular waveguide with an anisotropic uniaxial plate

Two-level systems (TLSs) are known to be a dominant source of dissipation and decoherence in superconducting qubits. Superconducting resonators provide a convenient way to study TLS-induced loss due to easier design and fabrication in comparison with devices that include nonlinear elements such as Josephson junctions. However, precisely measuring TLS-induced loss in a resonator in the quantum regime is challenging due to low signal-to-noise ratio (SNR) and the temporal fluctuations of the TLS, leading to uncertainties of 20% or more in the loss measurement. To address these limitations, we develop a multiwavelength resonator device that extends the resonator length from a standard quarter wavelength λ / 4 to N λ / 4 , where N = 37 , at 6 GHz. This design provides two key advantages: the TLS-induced fluctuations are reduced by a factor of N due to spatial averaging over an increased number of independent TLSs, and the measurement SNR for a given intraresonator energy density increases by a factor of N . The multiwavelength resonator also has fundamental and harmonic resonances spanning a wide frequency range, allowing one to study the frequency dependence of TLS-induced loss. In this work we fabricate both multiwavelength and quarter-wave coplanar waveguide resonators formed from thin-film aluminum on a silicon substrate, and characterize their TLS properties at 10 and 200 mK. Our results show that the power-dependent TLS-induced loss measured from the N λ / 4 resonator agrees well with that measured from the λ / 4 resonator, while achieving a fivefold reduction in measurement uncertainty due to TLS fluctuations, down to 5 % . The N λ / 4 resonator also provides a measure of the fully unsaturated TLS-induced loss due to the increased measurement SNR at low intraresonator energy densities. Finally, measurements across seven harmonic resonances of the N λ / 4 resonator between 4 and 6.5 GHz reveal no frequency dependence in the TLS-induced loss over this range. These results highlight the benefits of the multiwavelength resonator approach for material development in superconducting quantum circuits.

We investigated the loss mechanisms of superconducting circuits with epitaxially grown NbN(100) on MgO(100) substrates by measuring quarter-wave coplanar waveguide resonators with various strip and slot widths. The power dependence of the internal quality factor and the temperature dependence of the resonance frequency shift were evaluated in a dilution refrigerator. The measurement and analysis of the loss in these resonators indicate that the loss was dominated by a two-level system (TLS) loss and the TLS host materials were primarily distributed at the surface of the substrate.

This work presents, for operation at millimeter-wave frequency, a transition between an integrated circuit and a flexible plastic dielectric rod waveguide attached perpendicularly to the circuit. A transition featuring low loss, small chip-area consumption and ease of mechanical alignment is obtained by a combination of an on-chip spherical dielectric resonator and a metallic circular waveguide resonator. The flexible plastic wire can be operated in two orthogonal polarization modes, thereby doubling the transmission capacity. Transmission loss of the transition from on-chip microstrip line to Teflon plastic wire is extracted from measurements. For the single-mode transition, transmission is -3.7 dB and -3.2 dB at 62 GHz and 103 GHz, respectively. For the dual-mode transition, loss is about 0.4 dB higher.