Frequency Reconfigurable U-Slot Antenna for SDR Application

Abstract

Abstract-In this paper, a novel frequency reconfigurable U-slot microstrip antenna with T-shaped feed line for Software Defined Radio applications is proposed. The proposed antenna, indexed as A-I in this paper, operates at three different frequencies: 1.85 GHz, 1.9 GHz and 2.4 GHz depending on the switching states of PIN diodes. Furthermore, to strengthen the proposed design concept and strategy another improved antenna (A-II) is designed and tested. In comparison to antenna A-I, the improved antenna design (A-II) utilizes four slots/PIN diodes in order to increase the number of reconfigurable frequency states. Depending on the switch states of four PIN diodes, antenna A-II operates on five different reconfigurable frequency bands centered at: 1.5 GHz, 1.6 GHz, 1.8 GHz, 1.9 GHz and 2.24 GHz. The measured results show a return loss better than 22 dB, maximum gain of 2.5 dB and maximum efficiency of 78%. Moreover, radiation pattern for the proposed antennas is stable at all operating frequencies.

Microstrip antenna from silver nanoparticles printed on a flexible polymer substrate

“…The measured values at the frequencies of 2.02 GHz, (-16.02 dB) and 2.3 GHz, (-19.33 dB) make it possible for the antenna to be used in various applications such as mobile devices [27] and SDR (Software Defined Radio) [28]. Also another advantage is the fact that the PET substrate is very thin and the whole antenna is very light.…”

An Integrated Frequency Reconfigurable Antenna for Cognitive Radio Application

“…In case 3 , when diode D 1 and D 2 is forward biased by applying +5 V on DC pad V 1 and V 2 then active feed portion is F 1 along with stub 1 and stub 2 . In this case, the simulated frequency is 5 GHz with RL = 30 dB whereas the measured frequency is 5.15 GHz with RL = 30 dB as shown in Fig.…”

“…In case 4 , when either of diode D 3 or D 4 is forward biased then either stub 3 or stub 4 is selected to tune the resonating frequency for dual band. Again in this case, due to the geometrical symmetry of F 1 S 3 or F 1 S 4 structure because of the same geometrical parameters of stub 3 and stub 4 , their resonating frequency is found the same for both cases. So only the results for F 1 S 3 are given here.…”

“…Such antenna has a spectrum-sensing antenna for detecting the spectrum condition and reconfigurable antenna for communicating purpose [1], [2]. Many antenna designs have been already reported in the literatures, which are compatible with CR [3][4][5][6]. Further to decrease the system size, these two antennas must be optimally design on a single substrate.…”

A Wide Spectrum Sensing and Frequency Reconfigurable Antenna for Cognitive Radio

“…Moreover, either lumped or microstrip-based matching network is added to match the narrowband antenna at primary frequency, and then extra matching circuitry is needed to make the design frequency reconfigurable. In these designs, frequency switching is realized by using PIN diodes [8,12], varactors [6], field effect transistor (FET) switches [13]. The frequency reconfigurable operation demands increase in a number of frequency states, hence higher number of switches together with their biasing elements are needed resulting in increase in total cost and design complexity.…”