In this work, the feasibility of microwave liquid crystal based dielectric waveguide phased shifters is investigated in a phased rod antenna array for the first time. For this, a 1 × 4 rod antenna array is designed including the phase shifters as well as a cascaded E-plane power divider network. As core elements, the phase shifter are designed as continuously tunable subwavelength fibers, partially filled with a newly specifically synthesized microwave liquid crystal, exhibiting a maximum FoM 145 • /dB at 102.5 GHz. As proof-of-concept, a simplified electric biasing network is developed, demonstrating its beam steering capability by changing the scanning angle between 0 • , −25 • and +15 • with three different voltage distributions. The antenna array is well matched throughout the complete W-band with a input reflection below −10 dB. The measured antenna gain is between 11.5 to 9.1 dBi at 85 GHz accompanied with a side lobe level between −12 to −7 dB, depending on the steering configuration.INDEX TERMS Phased array, millimeter wave devices, microwave liquid crystal, dielectric waveguide.
This paper reports on an ultra-wideband (UWB) Schottky diode based balanced envelope detector for the L-, S-, C-and X-bands. The proposed circuit consists of a balun that splits the input signal into two 180º out of phase signals, a balanced detector, that demodulates the two signals, a low pass filter that rejects the second harmonic spurious from the Schottky diode and a bias tee that selects the optimum rectification point. The manufactured prototype is able to demodulate error free a 4 Gbps amplitude shift keying (ASK) signal at 4 GHz carrier frequency, leading to a record bitrate to frequency carrier ratio (b) of 100%. Besides this, the detector achieves error free demodulation for carrier frequencies between 4 and 8 GHz, while keeping the bitrate at 4 Gbps.
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