Single-pole Double-throw Switch Research Articles

Low‐cost ultra‐wideband discrete SPDT switch for K–Ku band in automotive applications and fifth‐generation systems

AbstractThe article details the development and production of an ultra‐wideband discrete single‐pole‐double‐throw (SPDT) Switch, measuring , and functioning within the 23.4–31 GHz frequency range, encompassing 24 and 28 GHz. This switch is specifically engineered to bolster high‐frequency systems in automotive and fifth‐generation applications. Our findings demonstrate that the discrete SPDT switch performs on par with integrated circuits while delivering consistent performance throughout its frequency spectrum. Furthermore, it offers a cost‐effective fabrication process. The switch exhibits an insertion loss ranging from 1.6 to 2.2 dB, with return loss and isolation surpassing 15 and 25 dB, respectively, across the majority of the frequency bandwidths.

A 28 GHz GaN 6-Bit Phase Shifter MMIC with Continuous Tuning Calibration Technique.

A 28 GHz digitally controlled 6-bit phase shifter with a precision calibration technique in GaN high-electron mobility transistor (HEMT) technology is presented for Ka-band phased-array systems and applications. It comprises six stages, in which stages 1 and 2 for 5.625° and 11.25° are designed in the form of a switched-line circuit, and stages 3, 4, and 5 for 22.5°, 45°, and 90° are designed in the form of a switched-filter circuit. The final stage 6 for 180° is designed in a single-to-differential balun followed by a single-pole double-throw (SPDT) switch for achieving an efficient phase inversion. A novel continuous tuning calibration technique is proposed to improve the phase accuracy. It controls the gate bias voltage of off-state HEMTs at the stage 6 SPDT switch for fine calibration of the output phase. Fabricated in a 0.15 μm GaN HEMT process using a die size of 1.75 mm2, the circuit produces 64 phase states at 28 GHz with a 5.625° step. The experimental results show that the Root-Mean-Square (RMS) phase error is significantly improved from 8.56° before calibration to 1.08° after calibration. It is also found that the calibration does not induce significant changes for other performances such as the insertion loss, RMS amplitude error, and input-referred P1dB. This work successfully demonstrates that the GaN technology can be applied to millimeter-wave high-power phased-array transceiver systems.

Flexible Design Method for Multifunctional Filtering Diplexers Integrated With Single-Pole Double-Throw Switches

Flexible Design Method for Multifunctional Filtering Diplexers Integrated With Single-Pole Double-Throw Switches

Multifunctional Quad-Channel Diplexer-Integrated Single-Pole Double-Throw Switch With Three Operating Modes

Multifunctional Quad-Channel Diplexer-Integrated Single-Pole Double-Throw Switch With Three Operating Modes

High isolation of SPDT PIN diode switch using switchable dumbbell-shaped DGS in millimeter wave 28 GHz band

This paper proposes a high isolation of single pole double throw (SPDT) PIN diode switch using switchable dumbbell-shaped defected ground structure (DGS). The proposed SPDT switch was designed for radio frequency (RF) front-end transceiver of antenna array multiple input multiple output (MIMO) in millimeter wave 28 GHz band. The switchable dumbbell-shaped DGS can be switched between allpass and bandstop responses where the bandstop response of the DGS can be utilized as a high isolation in the SPDT PIN diode switch circuit. A simple mathematical analysis is explained in this paper for the bandstop and allpass responses of the switchable dumbbell-shaped DGS. The propose SPDT switch was designed based on Roger RT/Duroid 5880 with 0.254 mm thickness and relative dielectric constant of 2.2. The simulated result showed that the proposed SPDT PIN diode switch produced an isolation of 36.36 dB at 27.3 GHz (center of 28 GHz band), which was 63% higher than the conventional SPDT design.

An Ultra-Wideband, High Power and High Isolation Single-Pole-Double-Throw Switch Using Capacitive Loading Approach

This paper presents an ultra-wideband, series-shunt type single-pole-double-throw (SPDT) switch with high isolation and good power handling capability from DC to 40 GHz. A new topology using capacitive loading on the shunt arms was proposed to improve the isolation across the entire band. The effect of the capacitive loading has been theoretically analyzed. Using the simple SPDT topology with one shunt arm as comparison, the capacitive loading approach exhibited an improvement of 5.9 dB in isolation at 40 GHz. To enhance the power handling capability, the stacked-FET configuration was adopted at the shunt arms. The optimum design has been implemented in the commercially available 0.15-lm GaAs pseudomorphic high-electron-mobility transistor (pHEMT) process and demonstrated an insertion loss of less than 3 dB, an isolation of greater than 39 dB, and an input 1-dB compression point (P1dB) of better than 32 dBm from DC to 40 GHz. To our knowledge, the proposed SPDT switch demonstrates the highest isolation over the widest bandwidth among other reported works to date.

Non-Contact Adaptive Voltage Sensor Based on Electric Field Coupling Principle.

Non-contact voltage sensors based on the principle of electric field coupling have the advantages of simple loading and unloading, high construction safety, and the fact that they are not affected by line insulation. They can accurately measure line voltage without the need to connect to the measured object. Starting from the principle of non-contact voltage measurement, this article abstracts a non-contact voltage measurement model into the principle of capacitive voltage sharing and deduces its transfer relationship. Secondly, it is theoretically inferred that the edge effect of the traditional symmetric structure sensor plate will cause the actual capacitance value between the sensor plates to be greater than the theoretically calculated capacitance value, resulting in a certain measurement error. Therefore, the addition of an equipotential ring structure is proposed to eliminate the edge additional capacitance caused by the edge effect in order to design the sensor structure. In addition, due to the influence of sensor volume, material dielectric constant, and other factors, the capacitance value of the sensor itself is only at pF level, resulting in poor low-frequency performance and imbuing the sensor with a low voltage division ratio. In this regard, this article analyzes the measurement principle of non-contact voltage sensors. By paralleling ceramic capacitors between the two electrode plates of the sensor, the capacitance of the sensor itself is effectively increased, improving the low-frequency performance of the sensor while also increasing the sensor's voltage division ratio. In addition, by introducing a single pole double throw switch to switch parallel capacitors with different capacitance values, the sensor can have different voltage division ratios in different measurement scenarios, giving it a certain degree of adaptability. The final sensor prototype was made, and a high and low voltage experimental platform was built to test the sensor performance. The experimental results showed that the sensor has good linearity and high measurement accuracy, with a ratio error of within ±3%.

Design and Analysis of Complementary Metal–Oxide–Semiconductor Single-Pole Double-Throw Switches for 28 GHz 5G New Radio

We propose a single-pole double-throw (SPDT) switch with low insertion loss (IL), high isolation, and high linearity for a 28 GHz 5G new radio. The transmit (TX) path is a π-network consisting of a parallel dynamic-threshold metal–oxide–semiconductor (DTMOS) transistor, M1, with large body-floating resistance, RB (DTMOS-R M1), a series one-eighth-wavelength (λ/8) transmission line (TL), and a parallel capacitance, Cant. The series λ/8-TL in conjunction with the parallel Cant and transistors’ capacitance constitute an equivalent λ/4-TL with a characteristic impedance of 50 Ω. This leads to low IL in the TX mode and decent isolation in the receive (RX) mode. The RX path is an L-network constituting a series impedance (of parallel inductance L1 and DTMOS-R M2) and a parallel DTMOS-R M3. This leads to a decent IL in the RX mode and isolation in the TX mode. The first SPDT switch (SPDT SW1) is designed and implemented in a 90 nm complementary metal–oxide–semiconductor (CMOS) with a top metal thickness (TMT) of 3.4 μm. A comparative SPDT switch (SPDT SW2) in a 0.18 μm CMOS with a thinner TMT of 2.34 μm is also designed and implemented. In the TX mode, SPDT SW1 achieves a measured IL of 0.67 dB at 28 GHz and 0.58–1 dB for 17–34.9 GHz and a measured isolation of 44.3 dB at 28 GHz and 25.6–62.3 dB for 17–34.9 GHz, one of the best IL and isolation results ever reported for millimeter-wave CMOS SPDT switches. The measured input 1 dB compression point (P1dB) is 28.5 dBm at 28 GHz. Moreover, in the RX mode, SPDT SW1 attains a measured IL of 1.9 dB at 28 GHz and 1.83–2.1 dB for 25–38.3 GHz and an isolation of 25 dB at 28 GHz and 24.5–27 dB for 25–38.3 GHz. The measured P1dB is 24 dBm at 28 GHz.

A Sigma-Delta Modulator with Single-Pole Double-Throw Analog Switch

In this paper, a high precision and high energy efficiency discrete-time switching capacitive 3-order Sigma-Delta modulator (SDM) is proposed. The SDM is applied to portable electroencephalograms (EEG) because of its little energy and good performance. The energy efficiency levels of the current mainstream modulator systems are analyzed and compared, and the CIFF modulator architecture which is most conducive to realizing high energy efficiency is selected. The single-loop CIFF structure is selected to give consideration to the accuracy and stability of the circuit. The circuit is implemented in a hierarchical structure, and a single-pole double-throw (SPDT) analog switch is adopted to overcome the difficulty of opening conventional CMOS analog switches at low supply voltages and the increase in threshold voltage Vth of NMOS devices due to the base bias effect. The proposed discrete-time Sigma delta ADC modulator is designed with SMIC 0.18um CMOS technology and achieves an SNDR of 101.6dB under a 1.8V power supply voltage and a signal bandwidth of 2kHz. The power consumption is 520uW and the significant bit (ENOB) is 16.58 bits.

Dual-Band Single-Pole Double-Throw Filtering Switch Using Multimode Cavity Resonators

A dual-band single-pole double-throw (SPDT) filtering switch using hybrid microstrip-cavity structure is proposed in this paper. Two rectangular cavities act as the multimode resonators, and the cross-shaped microstrip lines (MLs) are adopted to feed them. Then two filtering channels are constructed, while only one channel is supposed to be turned on in each operating state. For this purpose, PIN diodes are integrated into the two output MLs to switch the two channels arbitrarily. The channel using reversely biased PIN diodes is turned on with dual-band filtering response. On the contrary, the other channel using forward biased PIN diodes is switched off with high OFF-state suppression and channel isolation. The measurements indicate a dual-band filtering response along with below 0.75 dB insertion loss in the switched-on channel. And 38 dB suppression as well as 33.3 dB channel isolation is obtained in the switched-off channel. Benefitting from the hybrid microstrip-cavity structure, the bandwidths of the two bands could be adjusted independently. And meanwhile the two multimode cavities are shared by the two channels to compact the size. In this way, the proposed microstrip-cavity structure possesses a dual-band SPDT filtering switch response, flexible passbands and miniaturization.

A 1.65 to 1.84 GHz Filtering SPDT Switch With Fully Tunable Insertion Phase Using NRN and Mixed Electromagnetic Coupling Techniques

This paper presents a novel filtering single-poledouble-throw (SPDT) switch with continuously tunable center frequency and insertion phase. It is comprised of six varactorloaded microstrip resonators and three tunable non-resonating nodes (NRNs) at source and loads. The controllable mixed electromagnetic couplings are introduced on the two main paths of each channel of the switch. At ON-state, the designed filtering switch can generate a 4th-order bandpass filtering performance with high selectivity, and the insertion phase can be continuously tuned with a full 3600 tuning range by changing the reactances of NRNs and switching the dominated modes of the mixed couplings. At OFF-state, the mixed electromagnetic couplings are set to zero, and hence high isolation can be realized. To validate the proposed technique, a circuit prototype is designed and fabricated. The measured results suggest that the designed filtering SPDT switch can operate with a tunable center frequency ranging from 1.65 GHz to 1.84 GHz, and its insertion phase at ON-state channel can be continuously tuned from -1800 to 1800. During the whole tuning process, the measured in-band isolation for OFF-state channel keeps better than 40 dB.

A High-Power and Broadband GaN SPDT MMIC Switch Using Gate-Optimized HEMTs

A high-power, broadband monolithic microwave integrated circuit (MMIC) single-pole double-throw (SPDT) switch is designed with gate-optimized high-electron-mobility transistors (HEMTs) using AlGaN/Gallium nitride (GaN) technology. The foot length of the gate is varied from 200 to 250 nm, and the head length is varied from 500 to 750 nm in the T-gate structure to optimize the radio frequency (RF) performance. The SPDT switch is designed in a series–shunt–shunt topology using gate topology as a design parameter. The switch has achieved an insertion loss better than 0.75 dB throughout the 3.5–13.5-GHz bandwidth. It can transmit 30-W output power at 0.1-dB compression point and handle 47.5-dBm input power at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}_{\textrm{1\,dB}}$</tex-math> </inline-formula> . The isolation is above 25 dB, and the return loss is better than 11 dB. With its low insertion and high power-handling capacity in broadband, the SPDT switch shows state-of-the-art performance for high-power communication systems and radar applications.

A Sub-GHz CMOS SPDT Antenna Switch Employing Linearity-Enhanced Biasing Strategy for Second-Order Harmonic Reduction

A CMOS single-pole double-throw (SPDT) antenna switch employing linearity-enhanced biasing strategy is proposed for the second-order harmonic (H2) reduction. It was implemented and demonstrated using a 0.28-lm thick-oxide MOSFET in 65-nm CMOS process. The NMOS transistor of the conventional antenna switch is replaced with the CMOS transistor composed of an NMOS and PMOS transistor in parallel to improve second-order harmonic distortion (HD2). The optimum channel width of an NMOS and PMOS transistor is chosen to achieve odd symmetry characteristic of I-V curve with respect to the drain-to-source voltage swing (VDS), and, as a result, enhance HD2 of the antenna switch. In addition, the linearity-enhanced biasing scheme is adopted to the PMOS transistor as a conventional negative biasing method of the NMOS transistor. This prevents the degradation of the power handling capability in adopting the PMOS transistor to the antenna switch. In the measurement, the proposed single-stack SPDT antenna switch shows an insertion loss of less than 0.6 dB and an isolation of greater than 38 dB from 100 MHz to 1 GHz with an input and output return loss of greater than 25 dB. Concerning for H2 and third-order harmonic (H3), it shows H2 of -65 dBm and H3 of -90 dBm at 150 MHz when a single-tone RF signal with a power of +5 dBm is applied. Compared to the conventional NMOS-based antenna switch, the proposed CMOS-based antenna switch improves HD2 by approximately 8 dB, 7 dB, and 1 dB at 150 MHz, 400 MHz, and 1 GHz, respectively, while maintaining the comparable insertion loss, isolation, and third-order harmonic distortion (HD3).

Spiral-Resonator-Based Frequency Reconfigurable Antenna Design for Sub-6 GHz Applications

This paper presents a novel frequency reconfigurable antenna design for sub-6 GHz applications, featuring a unique combination of antenna elements and control mechanisms. The antenna is composed of an outer split-ring resonator loaded with an inner spiral resonator, which can be adjusted through the remote control of PIN diode or Single Pole Double Throw (SPDT) switches. The compact antenna, measuring 22 × 16 × 1.6 mm3, operates in broadband, or tri-band mode depending on the ON/OFF states of switches. The frequency reconfigurability is achieved using two BAR64−02V PIN diodes or two CG2415M6 SPDT switches acting as RF switches. SPDT switches are controlled remotely via Arduino unit. Additionally, the antenna demonstrates an omni-directional radiation pattern, making it suitable for wireless communication systems. Experimental results on an FR-4 substrate validate the numerical calculations, confirming the antenna’s performance and superiority over existing alternatives in terms of compactness, wide operating frequency range, and cost-effectiveness. The proposed design holds significant potential for applications in Wi-Fi (IEEE 802.11 a/n/ac), Bluetooth (5 GHz), ISM (5 GHz), 3G (UMTS), 4G (LTE), wireless backhaul (4G and 5G networks), WLAN (IEEE 802.11 a/n/ac/ax), 5G NR n1 band, and Wi-Fi access points due to its small size and easy control mechanism. The antenna can be integrated into various devices, including access points, gateways, smartphones, and IoT kits. This novel frequency reconfigurable antenna design presents a valuable contribution to the field, paving the way for further advancements in wireless communication systems.

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.

Measurement of Complex-Ratio Between Two RF Signals With Spectrum Analysis

A novel method to measure the amplitude-phase differences between two radio frequency (RF) signals is presented, based on spectrum analysis after periodic modulation. Two input signals are alternatively selected to enter the single-channel RF channel by a single-pole double-throw (SPDT) switch, which generates harmonics related to the channel unbalance. Amplitude-phase differences between two input signals can be obtained by analyzing the spectrum of received signal using discrete Fourier transform (DFT) in digital domain. Compared to conventional multichannel RF receivers, the proposed method has a concise structure and low-computational complexity. Simulation results are provided to verify its effectiveness over dynamic ranges of 60 dB and 360 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ$</tex-math> </inline-formula> . A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L$</tex-math> </inline-formula> -band RF circuit is fabricated to measure the amplitude-phase differences over 35 dB and 360 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ$</tex-math> </inline-formula> dynamic ranges. The measured results show good agreement to those by the vector network analyzer (VNA), certifying the effectiveness of proposed method.

A 28-GHz Four-Channel Beamforming Front-End IC With Dual-Vector Variable Gain Phase Shifters for 64-Element Phased Array Antenna Module

A 28-GHz fully differential four-channel beamforming front-end IC with variable gain phase shifters (VGPSs) is presented, of which orthogonal phase and gain control is achieved in a single block using the proposed dual-vector synthesis technique. This greatly reduces chip size, power consumption, and calibration complexity. The antenna switch embedded in the front-end matching network minimizes degradation of the transmitter (TX) efficiency and receiver (RX) noise figure. The multi-mode power amplifier (PA) with a built-in linearizer is presented to have high efficiency and linearity for all power modes, which reduces power consumption during gain control. Also, a differential four-way power divider and an single pole double throw (SPDT) switch are introduced in the common path, which has a small chip size and a low insertion loss. By adopting differential structures for all components in the four-channel IC, the effect of parasitic grounding inductances due to bonding and package is minimized. Thanks to the proposed dual-vector VGPS, the rms gain error of 0.21 dB and the peak phase variation of ±1.7° are achieved during phase control and gain control, respectively, without any calibration. The four-channel front-end IC also achieves rms phase error of only 1.4° during the simultaneous phase and gain control without any calibration. It has a TX OP1dB of 13.3 dBm and the highest linear output power of 7.2 dBm with 400-MHz 64-QAM fifth-generation (5G) new radio (NR) signals with 9.6-dB peak-to-average power ratio (PAPR). Also, this article presents a 64-element brick-type phased array antenna using four-channel core chips. It shows a high effective isotropic radiated power (EIRP) of 54.4 dBm at 28 GHz. An over-the-air link is demonstrated with a competitive data rate of 4 Gb/s using 64-QAM waveforms over all scan angles at a distance of 100 m.

High isolation and high power of 0.13 µm CMOS SPDT switch using deep‐N‐well transistors and floating‐body technique in K‐band

AbstractA K‐band high isolation single‐pole double‐throw (SPDT) switch using a 0.13 µm CMOS process is presented. Two on‐state resistors of shunt Deep‐N‐Well (DNW) transistors are used to improve isolation. The floating‐body technique is utilized to enhance the power‐handling capability. The off‐state capacitors of two DNW transistors are employed to construct an impedance‐matching network. The switch achieves a measured insertion loss of 3.0–3.2 dB and an isolation of better than 35 dB from 17 to 27 GHz. A measured input 1 dB compression power (IP1dB) of 11.8 dBm is obtained at 24 GHz. The chip size of the proposed switch is 0.52 × 0.66 mm2 with a core area of only 0.33 × 0.27 mm2.

A Dual-Component Electric Probe Embedded With a 0°/180° Hybrid Coupler for Near-Field Scanning

In this article, a Ka -band dual-component electric probe is proposed in low temperature co-fired ceramic for near-field scanning, which consists of a sensing part of two symmetric L-shaped strips and a 0°/180° hybrid coupler. The responses to the tangential and normal electric components are outputted to the difference and sum ports without post-processing, to avoid the errors due to phase measurements at high frequencies. A grounded coplanar waveguide (GCPW) is used as a standard kit. Equations are derived carefully to take the imperfect terminations into account. To further improve the sensitivity and measurement efficiency, a low noise amplifier (LNA) and an absorptive single pole double throw (SPDT) switch are integrated with the probe. Simulated and measured results indicate that the probe can characterize the near electric field distributions within the band of 27.2–30 GHz, and the sensitivity of the active probe prototype is improved by 17–18 dB at 28 GHz when compared with the passive one. The passive probe prototype is utilized to scan the near electric field of an integrated transmitting front-end module at 28.5 GHz.

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.