For the transmission performances of the proposed OOK modulator, up to 10 Gb/s data rate is achieved from simulated results. However, limited by the demodulator, a data rate of only 2.5 Gb/s is measured. The demodulated waveform compared with the original PRBS-7 signal is shown in Figure 5. A $8 ns delay between the demodulated and original signal exist. Table 1 compares the performance of the proposed OOK fundamental modulator with the reported designs. Using 0.13 lm MOSFETs, this work realized terahertz band fundamental modulation with an IL of $4.9 dB and isolation higher than 13 dB, providing a great potential for terahertz gigabit-data-rate communications.
CONCLUSIONA fundamental OOK modulator for terahertz high-data-rate communication application is designed and implemented using 0.13 lm MOSFETs. By adopting series loads, on-/off-switching is achieved with an isolation above 13 dB. The IL of the modulator is 4.9 dB and a 2.5 Gb/s data rate is demonstrated.ABSTRACT: This article presents a new design of ultrawideband monopole antenna with multiresonance and dual band-notched characteristics. The proposed antenna consists of a square radiating patch with a pair of step-shaped slits, a feed-line, and a modified ground plane with pair of rectangular slits and inverted coupled U-shaped parasitic structure. In the presented design, by cutting two rectangular slits and also by embedding an inverted U-shaped parasitic structure in the air gap distance, additional resonances are excited and hence much wider impedance bandwidth can be produced, especially at the higher band that the antenna provides a wide usable fractional bandwidth of more than 120% (3-13.7 GHz). To create a single band-notched property, a pair of step-shaped slits was cut at the square radiating patch. Finally, by converting the inverted U-shaped parasitic structure to the W-shaped structure, good dual band-notched function is achieved. The measured results reveal that the presented monopole antenna offers a very wide bandwidth around of 5-6 and 7.25-7.75 GHz to suppress any interference from wireless local area network and downlink of X-band satellite communication systems, respectively. The designed antenna has a small size of 12 3 18 mm 2 .