High Isolation Of Single Pole Double Throw Switch With Switchable Resonator For Wireless Communications

In wireless communication systems, Single Pole Double Throw (SPDT) switches are widely used in radio frequency (RF) front-end system to support transmit and receive modes switching for Time Division Duplex (TDD)communication. High isolation between transmitter and receiver in the RF front-end is one of the key parameters in SPDT switch design, especially for high power applications such as a base station and wireless infrastructure. Therefore, this research work introduced a new high isolation of SPDT discrete switch design using switchable resonator that includes minimum number of PIN diodes or produce absorptive feature. The microstrip resonators such as a transmission line stub, radial stub, parallel coupled line and ring were selected in this research work. By analyzing a mathematical model of simplified SPDT switch with resonator, a high isolation could be achieved due to a bandstop response of the resonators. These resonators were able to reconfigure between bandstop and allpass or bandstop and bandpass responses to support transmit and receive modes switching. The proposed SPDT switches with switchable resonator were demonstrated for the applications of Time Division Synchronous Code Division Multiple Access (TDSCDMA) in 2 GHz band and Worldwide Interoperability for Microwave Access (WiMAX) and Long Term Evolution (LTE) in 3.5 GHz band. Results showed that isolation of more than -25 dB was achieved in the SPDT discrete switch design using these four types of switchable resonators and suitable for high power application with 1 Watt and 10 Watt transmit output power. Despite high isolation performance, the proposed SPDT switches (with transmission line stub and radial stub resonators) used a minimum number of PIN diodes compared to conventional multiple cascaded switches technique. Meanwhile, the proposed SPDT switches (with parallel coupled line and ring resonators) produced high isolation with absorptive feature without additional circuit components

A Novel UWB Reconfigurable Filtering Antenna Design With Triple Band-Notched Characteristics By Using U-Shaped Coppers

This paper proposed an UWB antenna with triple reconfigurable notch filters. By presenting there U-shaped coppers in the design, the potential triple interference in UWB applications can be rejected. Six PIN diodes are putted on the coppers to represent the OFF and ON tunable status in order to add reconfigurable characteristics to the UWB antenna. By using this ON and OFF tunable method, the current distribution of the proposed design changes and enables the antenna to have eight operation modes. The results prove that the proposed design can operate over the entire UWB frequency range (3.1 GHz to 10.6 GHz) and can filter out the target signals from the WLAN upper band (5.725 to 5.825 GHz), WLAN lower band (5.15 to 5.35 GHz) and X band frequency system (7.9 to 8.4 GHz) in one of the tunable configuration

Design of a compact multifunctional power divider loaded with short-ended stub

The article presents a compact multifunctional power divider loaded with short-ended stub for RF front end system at 2.5 GHz application. The proposed structure consists of PIN diodes and short-ended stub at the output transmission line. Wilkinson power divider and SPDT switch at 2.5 GHz can be achieved by changing the bias voltage of the integrated PIN diodes. As the proposed design transitions from a power divider to an SPDT switch, a short stub is introduced at the output ports to prevent mismatches from occurring. The proposed SPDT switch design has been mathematically analyzed and presented in detail. Two frequency component functions are combined in a small package with three RF connectors. This proposed design is constructed and characterized for experimental-demonstration purposes. The method proposed in this article is simpler compared to the previous work and easy to fabricate. This technique will reduce the overall size and manufacturing cost. It also can be applied to design the multifunctional power divider at any desired specifications and operating frequencies that compatible with RF/microwave applications, such as smart antennas and phase-array antennas

Reconfigurable Feeding Network With Dual-Band Filter For Wimax Application

Design and simulation for reconfigurable Wilkinson Power Divider (WPD) related to WiMAX application is proposed in this paper. This proposed design relates to dual band WiMAX frequencies at 2.5 GHz and 3.5 GHz. The main purpose of this design is to design a switchable feeding network that can cover the WiMAX standards by reconfiguring the microstrip line length using PIN diode switches. Besides, the power divider also can be design and develop as power combiner due to the passive component structure and hence reciprocal. In this proposed Wilkinson power divider, different band of frequencies for WiMAX application are obtained by using PIN diode. By turning ‘ON’ and ‘OFF’ the PIN diode, different frequencies are achieved between 2.5 and 3.5 GHz. This proposed design used Rogers RO4350 (er = 3.48, h = 0.508mm) as a substrate material and copper (thickness = 0.002 mm) related to patch of design. This simulation results showed that the S11 is less than -15dB; and S12 and S13 are better than -5dB. Based on these simulation results, the proposed WPD design using dual-band filter was well applied where it has better return loss (S11) with less than -15 dB for both WiMAX frequencies

A Compact Reconfigurable Dual Band-Notched Ultra-Wideband Antenna using Varactor Diodes

In this paper, a reconfigurable dual band-notched ultra-wideband (UWB) antenna is presented. The antenna design consists of a circular shape with two pairs of the L-resonator. To realize the notch characteristics in WLAN at 5.2 GHz and 5.8 GHz bands, the half wavelength of the L-resonator is introduced in the design. The T-shaped notch is etched in the ground to enhance the bandwidth which covers the UWB operating frequency range from 3.219 – 10.863 GHz. The proposed reconfigurable dual band-notched UWB antenna shows good impedance matching for the simulated in the physical layout. Furthermore, the proposed antenna has a compact size of 37.6 x 28 mm2. This proposed reconfigurable design can provide an alternative solution for the wireless system in the designing of a band-notched antenna with a good tuning capability

Compact V-Shaped MIMO Antenna For LTE And 5G Communications

A new small V-shaped MIMO antenna with dimensions of the antenna 21 × 24 × 0.8 mm within the bands of (4.4-4.9) and (5.15-5.925) GHz was designed, and the fabrication and measurement outcomes derived from the use of the MIMO prototype revealed that the fractal MIMO antenna. The small and simple fractal antenna demonstrated high isolation of less than -18.5 dB and envelope correlation coefficient less than 0.05. These attributes are suitable for mobile, which is being introduced into Japanese markets

Fixed And Selectable Multiband Isolation Of Double Pole Double Throw Switch Using Transmission Line Stub Resonators For Wimax And Lte

A novel selectable multiband isolation of Double Pole Double Throw (DPDT) switch with switchable transmission line stub resonators has been proposed for applications of WiMAX and LTE in 2.3 and 3.5 GHz bands. In this paper, two DPDT switch designs are proposed; the first design is a fixed DPDT switch, and the second is a selectable DPDT switch. The second design allows selecting only one band and unselecting the other or selecting both of them. However, the first design does not allow so. The transmission line stub resonator used in this design is an open stub resonator with quarter wave of the electrical length. By using a simple mathematical model, the theory of the transmission line stub resonator was discussed where it can be cascaded and resonated at center frequencies of 2.3 and 3.5 GHz. Moreover, the cascaded transmission line stub resonators can be reconfigured between allpass and bandstop responses using discrete PIN diodes. The key advantage of the proposed DPDT with switchable transmission line stub resonators is a multiband high isolation with minimum number of PIN diodes. Therefore, the simulated and measured results showed less than 3 dB of insertion loss, greater than 10 dB of return loss and higher than 30 dB of multiband isolation in 2.3 and 3.5 GHz bands

Compact V-Shaped MIMO Antenna For LTE And 5G Applications

A compact sierpinski MIMO antenna was designed in the bands of 4.4 - 4.9 GHz and 5.15 - 5.925 GHz.The proposed dimension of the antenna were 21 × 24 × 0.8 mm, and was fabricated with inexpensive FR4 substrate with a thickness of 0.8 mm, a dielectric constant of 4.3, and 0.035-mm thick copper lining. The fabrication and measurement outcomes derived from the MIMO prototypes revealed that the proposed MIMO antennas are better in terms of size, isolation and the ECC. These attributes are suitable for LTE and 5G smartphone applications, which are being introduced into Chinese and Japanese markets

Selectable Multiband Isolation Of Single Pole Double Throw Switch Using Transmission Line Stub Resonator For Wimax And Lte Applications

This paper presents a selectable multiband isolation of Single Pole Double Throw (SPDT) switch with switchable transmission line stub resonators for applications of WiMAX and LTE in 2.3 and 3.5 GHz bands. Two SPDT switches are presented. (Design 2) either allows selecting only one band while unselecting the other or selecting both of them. However, (Design 1) does not allow so. The transmission line stub resonator used in this design is an open stub resonator with quarter wave of the electrical length. By using a simple mathematical model, the theory of the transmission line stub resonator was discussed where it can be cascaded and resonated at center frequencies of 2.3 and 3.5 GHz. Moreover, the cascaded transmission line stub resonators can be reconfigured between all-pass and band-stop responses using discrete PIN diodes. The key advantage of the proposed SPDT with switchable transmission line stub resonators is a multiband high isolation with a minimum number of PIN diodes. Therefore, the simulated and measured results showed the followings: less than 3 dB of insertion loss, greater than 10 dB of return loss and higher than 30 dB of multiband isolation in 2.3 and 3.5 GHz bands

Switchable Radial Stub Resonator for Isolation Improvement of SPDT Switch

This paper proposes switchable radial stub resonator for isolation improvement of Single Pole Double Throw (SPDT) discrete switch for Time Division Duplex (TDD) switching of wireless communications. A commercialized discrete PIN diode is used to switch the radial stub resonator between bandstop to allpass response where an analytical modeling of the switchable resonator is presented and analyzed. In this analysis, correlation between inner radial and angle radial stub with the characteristic impedance and attenuation pole is determined. Isolation improvement is analyzed with two-port network of single shunt PIN diode with switchable radial stub resonator where it is found that an additional isolation can be obtained with the switchable radial stub resonator. In measurement result, the SPDT switch with switchable radial stub resonator has shown more than 30 dB of transmit-receive (Tx-Rx) isolation at centre frequency of 3.5 GHz giving better isolation compared to conventional SPDT switch design. The potential application of this SPDT switch is TDD switching for WiMAX and LTE communication system