Abstract A novel wideband high-selectivity substrate-integratedwaveguide (SIW) filtering antenna with controllable radiation nulls is proposed. This antenna is composed of a two-layered SIW resonator, two radiating slots on the top layer, and two coupling slots on the middle layer. A vertical SMA connector is located at the bottom and feeds two SIW cavities simultaneously. By adjusting the parameters of these slots, three radiation nulls will be achieved, and two radiation nulls can be easily controlled. For demonstration, one prototype of the filtering antenna is fabricated and measured. Measurement results show that the fractional bandwidth for |S11| < -10 dB is 8.9% (3.86-4.23 GHz), the gain is 6.08 dBi at center frequency 4.05 GHz, three radiation nulls are achieved at 3.7 GHz, 4.3 GHz, and 5.19 GHz, respectively. The out-of-band skirt selectivities of two sidebands are 150 and 332 dB/GHz, respectively.

Abstract A novel planar balanced-to-balanced (BTB) microstrip filtering crossover with high isolation and common-mode (CM) suppression is proposed in this paper. The circuit structure is based on microstrip transmission lines without coupling sections, which can reduce insertion loss and enhance isolation. Specific theoretical analysis of the BTB filtering crossover configuration using transfer matrix and mixed-mode scattering parameters is performed. In order to verify the validity of the theory analysis and design, a microstrip BTB filtering crossover prototype at the center frequency of 2.45 GHz is fabricated and measured with high isolation and excellent CM suppression.

Abstract The biodegradation of synthetic dyes by fungi is emerging as an effective and promising approach. In the present study, freshwater fungal strains isolated from submerged woods were screened for the decolorization of 7 synthetic dyes. Subsequently, 13 isolates with high decolorization capability were assessed in a liquid system; they belonged to 9 different fungal species. Several strains exhibited a highly effective decolorization of multiple types of dyes. New absorbance peaks appeared after the treatment with 3 fungal strains, which suggests that a biotransformation process occurred through fungal biodegradation. These results showed the unexploited and valuable capability of freshwater fungi for the treatment of dye-containing effluents. The ability of certain fungi to decolorize dyes is reported here for the first time.