Single-pole Single-throw Research Articles

Design of BPF-Integrated SPDT Switch Based on Slotline Resonators Loaded With Diodes

Slotline Stepped-impedance resonators (SIR) loaded with p-i-n diodes are used to develop bandpass filter (BPF) integrated switches in this brief. The loaded diodes are used to switch the resonant conditions of the short-ended slotline resonators. The equations for their resonant conditions under different loads at different locations are derived and discussed. With these derived equations, the switchable filters are designed and synthesized using the classical coupled-resonator filter theory. The design concept is demonstrated by a Cascaded Quadruplet (CQ) BPFintegrated single-pole single-throw (SPST) switch at center frequency f0 = 1 GHz with with 47.7 dB OFF-state suppression (OSS). Finally, two compact BPF-integrated single-pole double-throw (SPDT) switches are designed and fabricated. One of them combines source-load (S-L) coupling and introduces two additional zeros outside the desired passband to improve the frequency selectivity. The other on fractal common feeding line is developed to reduce the impact of accumulated residual admittances from OFFstate channels, which shows high roll-off rate of sidebands as well as high port-to-port isolation of 53.1 dB, and its overall circuit size is only 0.051 λg2.

Wideband Millimeter-Wave SPST Switch in 100-nm GaN-on-Si Using Strong Mutual Coupling

This article proposes a wideband millimeter-wave (mm-wave) single-pole single-throw (SPST) switch using strong mutual coupling. For on-chip switches, it is very challenging to realize wide bandpass characteristics, especially in mm-wave bands. To address this issue, a wideband switch topology using strong mutual coupling has been introduced, based on which the fractional bandwidth of SPST switch can be easily expanded to over 80%. In addition, the coupling structure using coupled lines is investigated to realize strong mutual coupling. For demonstration, one 20-44.8 GHz switch with two transmission poles (TPs) is designed and fabricated in 100-nm GaN-on-Si. Low ON-state minimum insertion loss of 0.62 dB, preferable return losses better than -20 dB, and small chip size of 0.165 are realized, respectively.

W-Band GaN HEMT Switch Using the State-Dependent Concurrent Matching Method

In this study, a W-band GaN single-pole single-throw (SPST) switch was designed. To realize the pass and isolation modes of the SPST switch, we proposed the design technique of a unit branch consisting of one transistor and one transmission. The characteristic impedance and length of the transmission line were determined by the impedance and the angle at which the straight line connecting the impedances of the on and off states of the transistor meets the real axis of the Smith chart. Using the design technique, the matching networks for the pass and isolation modes of the switch are concurrently completed. In order to improve the insertion loss and isolation characteristics of the switch, the size of the transistor and the number of unit branches were investigated. To verify the feasibility of the proposed design technique, we designed the W-band SPST switch using a 100 nm GaN HEMT process. The measured insertion loss and isolation were below 2.9 dB and above 23.5 dB, respectively, in the frequency range from 91 GHz to 101 GHz.

24–35 GHz Filtering LNA and Filtering Switch Using Compact Mixed Magnetic-Electric Coupling Circuit in 28-nm Bulk CMOS

This paper presents compact 24–35 GHz filtering low noise amplifier (LNA) and filtering switch in 28-nm CMOS technology. A compact mixed magnetic-electric coupling circuit is designed, where a transmission zero is introduced out of the passband due to the cancellation of the magnetic and electric couplings. By analyzing the impedance characteristics, this structure can be designed with the impedance conversion function to replace the widely used transformers in integrated circuit designs. It shows the advantages of easy control of coupling coefficient and out-of-band rejection. Then, an LNA employing the magnetic-electric coupling circuits as impedance matching networks is designed. Image rejection can be achieved without increasing the circuit area. Moreover, by loading transistors to this mixed magnetic-electric coupling circuit, the input impedance can be controlled by the parasitic components of the transistor. Subsequently, a filter passband can be switched on and off, realizing a very compact filtering single-pole single-throw (SPST) switch. The fabricated filtering LNA is measured with a 3-dB bandwidth of 24–35 GHz, a noise figure (NF) of 2.4-3.6 dB, a maximum gain of 22 dB, and suppression of better than 25 dBc below 18 GHz. The filtering switch shows a minimum on-state loss of 2.1 dB at 28.6 GHz with better than 12.9 dB rejection below 16 GHz and off-state isolation of higher than 19 dB.

Wideband-Filtering Switches With Ultra-Wide Stopband Using P-I-N Diodes Loaded on Slotline

This paper presents a new design method for the microwave switch, which uses p-i-n diodes loaded on slotline. A single-pole single-throw (SPST) switch based on the microstrip-slotline-microstrip (M-S-M) transition with non-uniform loading structures is first designed to validate our design approach, which controls the on and off states of the switch by applying different voltages to the diodes. Then a single-pole double-throw (SPDT) switch using p-i-n diodes loaded on slotline T-junction is proposed, which achieves great high-pass response of ON-state channel and 20 dB OFF-state suppression (OSS) within dc to 4.64 GHz. To overcome the poor selectivity of two switches, transmission zeros need to be introduced to achieve band-pass response. Therefore, the slotline of the M-S-M transition is loaded with gradient length short stubs to bring in multiple transmission zeros and achieve SPST/SPDT wideband-filtering switches with ultra-wide stopband. Finally, the proposed filtering switches are fabricated and measured. The measurement results show that the SPDT filtering switch not only provides the expected band-pass response and wide stopband from 4 to 43.5 GHz of ON-state channel, but also has 22.8 dB rejection of OFF-state channel, and the 20.8 dB port-to-port isolation from dc to 43.5 GHz.

An 11–40-GHz High-Power Switch With Miniaturized High-Order Topology Using 100-nm GaN-on-Si HEMTs

This article proposes an ultrawideband switch with miniaturized high-order topology. A 100-nm gate-length GaN-on-Si process is used for high-power capability, and the modeling of the GaN high-electron-mobility transistors (HEMTs) is given to analyze its parasitic values. For wideband or high isolation, the high-order switch is one solution, whose die area is naturally large. To address this issue, a miniaturized coupled-resonator switch topology was proposed using inverter transformation, where two parallel LC tanks and four inverters are replaced by two series LC tanks. Furthermore, a miniaturized coupling structure is introduced using a common inductor to replace three individual ones, contributing to an 86% size reduction. For demonstration, one 11–40.5-GHz single-pole single-throw (SPST) switch with four transmission poles (TPs) has been designed and fabricated. A small chip size of 0.32 mm2, low ON-state minimum insertion loss (IL) of 0.55 dB, and a high-power capability of 1.3 W are achieved.

Highly Selective Bandpass Switch Block With Applications of MMIC SPDT Switch and Switched Filter Bank

A new bandpass single-pole single-throw (SPST) switch (BPSW) is proposed in this letter. The proposed BPSW configuration can be directly employed as a building block to construct the single-pole N-throw (SPNT) switch or the highly-selective switched filter bank with no need for the extra control circuit, thus effectively reducing the circuit size and lowering the loss. The operation mechanism of the BPSW is analyzed, and the filter-synthesis-based design method is given. For demonstration, 3-6 GHz and 4-8 GHz BPSW blocks are built using the commercial GaAs pHEMT process to construct the single-pole double-throw (SPDT) switch as well as the two-way integrated switched filter bank. The filter bank is implemented in 0.25 μm GaAs pHEMT process. Two passbands are measured at 2.7-5.79 GHz and 3.72-7.35 GHz with a minimum insertion loss of 2.7 dB, while the all-OFF state can be set with over 35 dB suppression. The measurement results are in good agreement with the simulation that verifies the concept.

A Low-Band Multi-Gain LNA Design for Diversity Receive Module with 1.2 dB NF.

This paper presents and discusses a Low-Band (LB) Low Noise Amplifier (LNA) design for a diversity receive module where the application is for multi-mode cellular handsets. The LB LNA covers the frequency range between 617 MHz to 960 MHz in 5 different frequency bands and a 5 Pole Single Throw (5PST) switch selects the different frequency bands where two of them are for the main and three for the auxiliary bands. The presented structure covers the gain modes from −12 to 18 dB with 6 dB gain steps where each gain mode has a different current consumption. In order to achieve the Noise Figure (NF) specifications in high gain modes, we have adopted a cascode Common-Source (CS) with inductive source degeneration structure for this design. To achieve the S11 parameters and current consumption specifications, the core and cascode transistors for high gain modes (18 dB, 12 dB, and 6 dB) and low gain modes (0 dB, −6 dB, and −12 dB) have been separated. Nevertheless, to keep the area low and keep the phase discontinuity within ±10, we have shared the degeneration and load inductors between two cores. To compensate the performance for Process, Voltage, and Temperature (PVT) variations, the structure applies a Low Drop-Out (LDO) regulator and a corner case voltage compensator. The design has been proceeded in a 65-nm RSB process design kit and the supply voltage is 1 V. For 18 dB and −12 dB gain modes as two examples, the NF, current consumption, and Input Third Order Intercept Point (IIP3) values are 1.2 dB and 16 dB, 10.8 mA and 1.2 mA, and −6 dBm and 8 dBm, respectively.

28–38-GHz 6-bit Compact Passive Phase Shifter in 130-nm CMOS

In this letter, a highly compact, bidirectional, wideband 6-bit resolution passive phase shifter (PS) is presented in low-cost 130-nm CMOS technology. A compact Lange differential hybrid is designed in this letter to provide quadrature signals from the input. The compact Lange hybrid is followed by a switching matrix that generates weighted sums of the quadrature signals to cover 360° and additional controlled loss using single pole single throw (SPST) switches. The matrix consists of 12 transistors, each of which is controlled by a three-level gate voltage (0, 0.6, and 1.2 V) providing higher resolution in phase shifts. The chip achieves the state-of-the-art performance with 10-dB insertion loss across 28–38 GHz. The chip also achieves an rms gain error of 0.6 dB and an rms phase error of 3° in the bandwidth, consuming no dc power and only 0.15 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> including baluns.

Analytical Design of Millimeter-Wave 100-nm GaN-on-Si MMIC Switches Using FET-Based Resonators and Coupling Matrix Method

This article presents an analytical design for millimeter-wave monolithic microwave integrated circuit (MMIC) switches. First, the field-effect-transistor-based (FET-based) resonator is proposed, whose resonant frequency and bandwidth can be controlled flexibly. As a result, the design flexibility of MMIC switches can be highly improved by using FET-based resonators. Second, a fast and flexible impedance matching technique is presented for MMIC switches based on the coupling matrix method. By selecting appropriate coupling parameters, the MMIC switches can be easily designed without designing multistage impedance matching circuits. In this way, low insertion loss (IL) and compact chip size can be accordingly obtained. For design validation, two single-pole single-throw (SPST) switch prototypes are designed and fabricated by using two or four FET-based resonators, respectively. Implemented in 100-nm GaN-on-Silicon HEMT process, high input 1-dB compression point (IP1 dB) of over 30 dBm is realized. The return losses are better than 15 dB, the minimum IL is only 1.1 dB at 30 GHz, and the isolations are higher than 45 dB. The above features indicate the validation of the proposed design method for MMIC switches.

A 24–44 GHz Broadband Transmit–Receive Front End in 0.13-μm SiGe BiCMOS for Multistandard 5G Applications

In this article, a novel broadband millimeter-wave (mm-wave) front end (FE) based on the asymmetric switch network structure is proposed for multistandard fifth-generation (5G) applications. The asymmetric switch network consists of a bidirectional impedance transformation network and a T-type topology single-pole single-throw (SPST) switch. In the TX-mode, the bidirectional impedance transformation network serves as an output matching network to achieve a continuous-mode Class-F <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> power amplifier (PA) to expand the bandwidth. In the RX-mode, the OFF impedance of the PA can be transformed into a high-impedance region by the bidirectional impedance transformation network. Based on the proposed structure, a broadband mm-wave front end is implemented in the 0.13- μm SiGe BiCMOS process, which occupies 906 μm ×997 μm including pads. In the TX-mode, the -1-dB P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sat</sub> bandwidth of the FE covers 21-44 GHz with the maximum output power of 18.1-19 dBm and the peak power added efficiency (PAE) of 20.2%-26.8%. In the RX-mode, the FE achieves an 84.6% and -3-dB small-signal gain fractional bandwidth from 20.2 to 49.8 GHz with 38-mW power consumption. It achieves a measured noise figure (NF) of 7.62-11.64 dB over the frequency range of 24-48 GHz. To the best of our knowledge, this is the first FE that covers all the present 5G mm-wave bands without reconfiguration.

A Beam-Switchable Self-Oscillating Active Integrated Array Antenna Using Gunn Oscillator and Magic-T

Herein, a novel self-oscillating active integrated array antenna (AIAA) is proposed for beam switching X-band applications. The proposed AIAA comprises four linearly polarized microstrip antenna elements, a Gunn oscillator, two planar magic-Ts, and two single-pole single-throw (SPST) switches. The in/anti-phase signal combination approach employing planar magic-Ts is adopted to attain bidirectional radiation patterns in the φ =90° plane with a simple structure. The proposed antenna can switch its beam using the SPST switches. The antenna is analyzed through simulations, and a prototype of the antenna is fabricated and tested to validate the concept. The proposed concept is found to be feasible; the prototype has an effective isotropic radiated power of +15.98dBm, radiated power level of +4.28dBm, and cross-polarization suppression of better than 15dB. The measured radiation patterns are in good agreement with the simulation results.

Integrated W-Band Photoconductive Switches in SIW Technology

A novel approach for the design of millimeterwave (mmWave) substrate-integrated waveguide (SIW) switches is presented. The switch is based on controllable photoconductive elements (PEs), whose conductivity is modulated by a light source. The PE is integrated on the top SIW metal plate and provides either a short-circuit or transmission operation regime, depending on the actuation conditions. Due to the light actuation, the mmWave and dc control circuitry are naturally decoupled, which, in turn, makes the design low-loss and compact as compared to p-i-n diode and integrated circuit-based SIW switches implementations. We demonstrate two examples of SIW photoconductive switches (PSs) at W-band: single-pole single-throw (SPST) and single-pole double-throw (SPDT) PSs. Their operation principle, actuation, and parasitic radiation suppression are discussed. Measurements show the peak insertion loss of 0.9 and 2.2 dB, isolation better than 25 and 30 dB, and -10 dB impedance bandwidth of 21% and 15% for the SPST and SPDT PSs, respectively.

A Broadband, mm-Wave SPST Switch With Minimum 50-dB Isolation in 45-nm SOI-CMOS

This article describes a single-pole, single-throw (SPST) CMOS switch aimed at integrated transceiver applications. The SPST switch realizes better than 50-dB isolation (ISO) across dc-to-43 GHz while maintaining an insertion loss (IL) below 3 dB. To maximize ISO, substrate coupling is compensated using bilateral RF signal cancellation in a fully differential circuit topology. Measured RF input power for 1-dB compression (IP1dB) of the IL is +19.6 dBm, and the measured input third-order intercept point is +30.4 dBm (both assuming differential inputs at 20 GHz). The prototype is fabricated in GlobalFoundries 45-nm RF-SOI CMOS technology and has an active area of 0.0058 mm2. Monte Carlo simulations predict variations due to processing of 8.3% and 2.75% in IL and ISO, respectively, ±0.2 dB variation (for both IL and ISO) from a 5% change in supply voltage, and ±0.1-dB variation (both IL and ISO) for a 0 °C–85 °C temperature sweep.

A DC to 220-GHz High-Isolation SPST Switch in 22-nm FDSOI CMOS

A wideband single-pole single-throw (SPST) switch covering the dc to 220-GHz frequency range is presented in this letter. A four-element distributed topology is used to extend operation to the upper millimeter-wave band. With a combination of front-gate and back-gate biasing, unique to fully depleted silicon-on-insulator (FDSOI) MOSFETs, and enabled by the thick metal/dielectric backend of the technology, the switch achieves an insertion loss of 3.1 dB and an isolation of 37 dB at 220 GHz, as well as a peak isolation of 58 dB at 200 GHz, without deembedding the pads. A G-band variable gain low-noise amplifier featuring the SPST switch shows >50-dB gain control range, with a maximum peak gain of 9.5 dB at 190 GHz and a 3-dB bandwidth from 180 to 203 GHz.

Gallium-Based Liquid Metal Substrate Integrated Waveguide Switches

This letter presents a new approach for reconfiguring substrate integrated waveguide (SIW) devices. It involves allowing or prohibiting the wave propagation by using a removable wall which is built from a series of drill holes. When the wall is required, the holes are filled with gallium-based liquid metal (LM), thus forming vias. When the wall is no longer required, the holes are emptied of LM. The method has been applied to a single-pole single-throw (SPST) SIW switch as well as a single-pole double-throw (SPDT) switch. Both switches perform well over a wide frequency bandwidth, approaching one octave. The SPST switch performs well from 2.4 to 4.3 GHz. In the ON-state (i.e., wall removed), the insertion loss (IL) is ≤0.5 dB. In the OFF-state (i.e., wall inserted), the isolation is 30 dB. The SPDT switch operates effectively from 4.7 to 7.2 GHz. The IL, between two connected ports, is 0.7 dB. The isolation between unconnected ports is 40 dB. The proposed approach will be applicable within a wide range of different reconfigurable microwave devices.

Considerations for Harmonics Distribution in Aperture-Tuned Inverted-F Antenna for Cellular Handheld Devices

An analysis of the harmonics distribution in the aperture-tuned inverted-F antenna (IFA) using the first-order transmission line model is presented. The analysis allows identifying local minimums for the second and third harmonics for a given use case, providing the mechanism for optimization of the nonlinear performance of an antenna system. The theoretical findings are verified on a hardware demonstrator, comprising a mechanically reconfigurable IFA and a single-pole single-throw (SPST)-based aperture tuning network. The aperture tuning network comprises a radio frequency (RF) high-voltage switch, including a voltage detector with low-harmonic feedback and a parallel inductor. The integrated circuit (IC) was fabricated in Infineon 130-nm dedicated RF switch technology. The hardware demonstrator enables the measurements of the impedance at the feed, harmonics, RF voltage along the radiating element, and impedance at aperture tuning port. The latter provides a mechanism for optimization of load impedance at integer multiplies of transmitted frequencies, which allows minimization of harmonic content generated by the tuning IC.

Low-Loss Polarization-Agile U-Band Switch

A low-loss U-band polarization-agile single pole single throw (SPST) circular waveguide switch with filtering capability is presented. This switch contains a diaphragm based on a ring slot with p-i-n diode switchable radial stubs situated at the cross-section of a circular waveguide. Commutation of the p-i-n diodes permits the control of the transmission characteristics for the incident linearly polarized wave with different orientations of its polarization vector. Due to the application of an original hybrid technology for the diaphragm fabrication, an insertion loss of 0.45 dB and an isolation of 20.6 dB are obtained near the central frequency of 50.0 GHz. The developed SPST switch is suitable for the usage in the antenna block of modern millimeter-wave receivers with polarization reuse due to the ultra-low insertion loss..

Piezoelectric RF MEMS Switches on Si-on-Sapphire Substrates

This paper reports the development of piezoelectrically actuated radio frequency (RF) micro-electromechanical systems (MEMS) switches on Si-on-sapphire substrates using a novel greyscale lithography fabrication technique. Lead zirconium titanate (PZT) thin-film actuators are used to close a series ohmic contact single-pole single-throw (SPST) switch implemented in co-planar waveguide (CPW). The switch design on a Si substrate has maximum insertion loss of 2.6 dB from DC - 67 GHz. While over the same frequency span, the switch on a sapphire substrate exhibits insertion loss better than 1.4 dB and isolation better than 15 dB.

Mm‐wave single‐pole single‐throw m‐HEMT switch with low loss and high linearity

This Letter presents a single-pole single-throw (SPST) switch for high-power applications in the mm-wave frequency band. A stacked-FET structure is adopted in the shunt switching cell for reducing the insertion loss and improving the linearity of the switch. To enhance the isolation, the parasitic inductance of the stacked-FET structure is resonated out by connecting a series capacitor. The number of stacked FETs in each shunt cell and the number of the shunt cells are optimised considering the trade-off among the insertion loss, isolation, and linearity. The SPST switch is fabricated in a 70-nm GaAs m-HEMT process. The measurement shows that the insertion loss is <1.1 dB, and the isolation is >25 dB over the frequency from 59 to 77 GHz. Both the insertion loss and isolation are not compressed at all until the input power reaches 19.5 dBm at 75 GHz.