Output coupled line wavelength hybrid ring resonator centered at 3 GHz for bandpass filter applications

An output coupled line wavelength ring resonator centered at 3 GHz operating frequency for bandpass filter application is presented in this paper. The proposed ring resonator demonstrates a single mode resonant frequency at 3 GHz with a pair of transmission zeroes. This ring resonator consists of even and odd mode line impedance, and coupled to the output feed lines along a quarter-wavelength of its side to generate a single-mode bandpass response with two transmission zeroes at 2 GHz and 3.5 GHz. The design of the resonator filter is simulated in Microwave Office (AWR Design Environment) based on the design specification and fabricated on Flame Retardant Type-4 (FR4) microstrip substrate with dielectric constant, εr=4 and height of thickness, H = 4 mm. All the simulation and measurement results are presented and discussed in this paper to show its feasibility.Keywords: line wavelength; ring resonator; two transmission zeroes; microwave filter; bandpass filte

Body Mass Index (BMI) Effect on Galvanic Coupling Intra-Body Communication

Intra-body communication (IBC) is a wireless communication system where human body is used as a signal transmission medium. Main advantage of IBC compared to other wireless communication is capable of low power consumption. There are two coupling methods in IBC, which are capacitive and galvanic coupling. The characteristic of human body play an important role in IBC because the transmitted signal is propagates through the body tissue. Therefore, this paper investigates the effect of different dielectric properties of body tissues to the quality of IBC signal transmission by focusing at body fat. Galvanic coupling method was used. 12 subjects were volunteered in this study and the value of subject’s body fat was differentiates by body mass index (BMI). The frequency was focused on 21 MHz, 50 MHz and 80 MHz. The signal quality at 21 MHz and 80 MHz shows the degradation as the increasing of body fat. The signal attenuation is increasing as body fat increased because in human body, the bone and fat has higher resistance than nerves and muscle. However, at frequency 50 MHz, the increasing of human BMI does not increase the attenuation where the attenuations are at peak value