Design of a compact reconfigurable bandpass filter using interdigital capacitor, DMS slots and varactor diode for wireless RF systems

This paper proposes a new design of a reconfigurable bandpass filter based on an interdigital capacitor and varactor diode for wireless and mobile applications. The designed reconfigurable bandpass filter has been implemented on an RT 6010 substrate with a relative dielectric constant of 10.2, thickness of 1.27 mm, and loss tangent of 0.0023. In order to reduce the filter size, the defected microstrip structure (DMS) is used due to its easy design, high compactness, high quality factor and easy integration with other RF devices. The suggested reconfigurable filter has a simple structure with a very attractive compact size of 4.7 × 8.4 mm2, low insertion loss than -1 dB, and tuning range (2–2.6 GHz).

A Frequency and Polarization Reconfigurable Dual-Patch Microstrip A Frequency and Polarization Reconfigurable Dual-Patch Microstrip

This paper proposes a reconfigurable microstrip patch antenna design for wireless ISM band applications. The antenna simultaneously uses PIN Diodes to switch between linear and circular polarization at 2.45 GHz and uses Varactor Diode to continuously tune the operating frequency from 1.73 GHz to 2.45 GHz. The antenna performance is characterized as a combination of ON/OFF state of PIN Diode and a bias voltage of Varactor Diode varying from 0.8V to 10V. A good agreement between simulation and measurement is obtained which validates the proposed method. The proposed frequency/polarization reconfigurable antenna is promising for various applications in wireless ISM band such as DCS (1710 – 1880 MHz), PCS (1850 – 1990 MHz), GSM 1800, GSM 1900, UMTS (1920 – 2170 MHz) and WiFi/Bluetooth (2.4 – 2.5 GHz).

Design of a continuously tunable reflectarray element for 5G metrology in the k-band

We introduce a new tunable reflectarray element for an operation frequency of 26 GHz in the k-band. It is shown that a 340∘ continuous tunning range of the reflected wave can be accomplished by using an aperture-coupled patch antenna with only one single varactor diode. The simplified design and the small needed space make it usable for k-band reflectarrays with many elements. The functionality of the reflectarray element is explained and the crucial parts are analyzed. The approach to get a full phase shift is discussed in detail. A bias-T is developed to provide the control voltage to the varactor diode without interfering with the high frequency path. The high frequency path and the DC-path are decoupled by 39 dB using a bias-T. A commercial off-the-shelf varactor diode is selected and its functionality at 26 GHz is verified. Therefore, a test printed circuit board with through, reflect, line standards is developed to de-embed the varactor diode and to evaluate it with a vector network analyzer. The reflectarray is simulated in a unit cell with plane wave excitation and periodic boundary condition using the simulation software package CST Microwave Studio™.