Reza Dehbashi

New Compact Size Microstrip Antennas With Harmonic Rejection

A new u-slot microstrip patch antenna with two types of feedings has been investigated. It has harmonic rejection property. In addition, the patch is compact and we have achieved a size reduction of about 40% and 31% of a conventional square patch antenna for inset- and probe-fed, respectively. The simulated results are verified by measurements

A Harmonic-Rejecting Inset-Fed U-Slot Antenna for Rectenna Application

A microstrip harmonic-rejecting inset-fed u-slot antenna at 2.4 GHz for rectenna application is proposed. Simulated results by using two commercial MOM method softwares ADS and Ensemble show that the u-slot antenna with inset feeding, occupies about 30% smaller physical area than the conventional microstrip inset-fed square-patch one. Also, the u-slot antenna exhibits high reflection coefficients at the second and third harmonics which is proper for rectenna application, because by rejecting the harmonics, generated by diode, the need for Band- Pass Filter (BPF) placed between the antenna and diode is eliminated. In addition the gain of the u-slot antenna is 6.9 dBi, while that of the square patch is 2.677 dBi.

Dual-Fed Antenna for Wireless Power Transmission and Data Communication

In this paper, a dual-fed antenna is designed. It functions as a rectenna from one port and as a data receiver from another port. It has two kinds of feed lines. One is microstrip feed line for energy receiving and probe feed line for data communication. Both of these ports have harmonic rejection property which is an important feature particularly for rectenna section. Using antenna with harmonic rejection, eliminates using matching network and band-pass filter (BPF) in rectenna systems. Therefore, our dual-fed antenna shows compact and multi function system. Moreover, it can be used as a self biasing data receiver because the rectenna part can provide the needed DC power for the biases of the data receiver

Active Integrated Antenna Based Rectenna using a New Probe-Fed U-Slot Antenna with Harmonic Rejection

Antenna array is an effective means to increase the receiving power for rectification. However, a tradeoff arises between the antenna size and the radiation gain. In this paper, an antenna that has a high radiation gain and yet is compact in size is proposed for the rectenna named c-shaped u-slot coaxial-fed microstrip antenna. The proposed antenna in comparison of the inset-fed square patch antenna, not only has physical dimensions 32% less than square patch antenna, but also it has a gain of 6.96 dBi, while the gain of the square patch one is 2.677 dBi. Hence, its characteristics are comparable to several element antenna array, but an extra feeding network is not required and the system is compact. Also, the concept of the active integrated antenna (AIA) is used to design an efficient rectenna. Under this concept the antenna can provide certain circuit functions such as resonating, filtering, duplexing and harmonic rejection, in addition to its original role as a radiating element. Our proposed antenna is a kind of AIA that has the harmonic rejection characteristic. Therefore the matching circuits and the band-pass filter (BPF) are not needed for the proposed design. Because a c-shaped u-slot antenna in the rectenna can suppress the 2nd and 3rd harmonics, the harmonic rejection BPF can be removed. Moreover the impedance of the rectifying circuit is matched to the input impedance of the c-shaped u-slot antenna using a coaxial feed and finding a proper point on the surface of the antenna without matching circuit

Analysis of a Novel Band-Stop Resonator by 3-D CFDTD Method

In this paper a miniaturized novel band-stop resonator has been introduced which can be used insteade of two cascaded radial stubs in wide bandwidth applications like rectennas for rejecting harmonics and bias-T circuits with wideband frequency rang for isolation between RF and DC part. This resonator is analyzed using 3-D Conformal Finite Difference Time Domain (CFDTD) method and compared the results with numerical ones obtained by MOM method commercial software ADS. The results shows 17.88% size reduction, and bandwidth improvement of scattering parameters |S12| and |S11| about 14% (<20 dB) and 13.15% (<3 dB), respectively.

A new compact biasing circuit for active integrated antenna and MMIC applications

In this work, a new bias-T circuit is introduced. It is not only 50% compact in comparison to conventional bias-T, but also the results of two commercial MOM method softwares ADS and Ensemble show all scattering parameters are improved. Therefore, it is proper for applications like AIA and MMIC where compactness is important

A novel miniaturized broad-band band-stop resonator used in rectennas in WiMAX frequency band

A novel compact broad-band band-stop resonator is introduced that can be used instead of two-radial stub resonator that in rectifying antennas (rectennas) is typically used. Using a commercial MOM method software ADS 2003 not only show the compactness of about 40% of the filter part of the rectenna but also the scattering parameters are improved. Moreover, theoretical analysis of this resonator based on expansion mode method is presented which matches well with simulation results

A novel broad-band band-stop resonator with compact size

In this paper a novel band-stop resonator has been introduced which can be used instead of two cascaded radial stubs in wide bandwidth applications. The results obtained by a commercial MOM method software (ADS) show by using this resonator, not only the physical area is reduced, but also the scattering parameters are improved. The improvements of scattering parameters |S11| (<3 dB) and |S12| (<20 dB) for trimmed novel resonator and conventional two radial resonator is 25% and 30.77%, respectively. This improvement for |S11| (<20 dB), |S12| (<3 dB) and |S13| (<30 dB) in bias-T application is 63.16%, 6.67% and 33.33%, respectively. Also the size reduction in comparison with conventional two radial resonator is 41.19% and 48.41%, respectively. So more reduction of physical area in bias-T application is applicable.