The size of the oscillator is 525 m m  120 m m (0.063 mm 2 ). 3 shows the fabricated ring oscillator with the function of oscillation control. Then, metal was deposited in the openings to form metal lines and bond pads by aluminum sputtering at a thickness of approximately 1 m m. After silicon oxide (SiO 2 ) was deposited by tetra-ethyl-ortho- silicate (TEOS), a 4 m m  4 m m contact hole was defined. Ions for the source and drain of MOS are implanted with boron (4  10 15 cm À 2, 80 keV) and phosphorous (4  10 15 cm À 2, 50 keV). The resistance of the poly-Si gate was measured as 14 O / &, and the thickness of the gate was 475 nm. Later phosphorous doped-poly-Si was formed for the poly-Si gate. Polycrystalline silicon (poly-Si) was deposited by low pressure chemical vapor deposition (LP-CVD). Gate oxide of the MOS ( t ox ) with thickness of 44 nm was formed by dry oxidation. The sheet resistance of the formed p-well was 2.45 k O / &. p-well was formed by ion implantation with boron (1.5  10 13 cm À 2, 60 keV) and drive-in for 9 h. n-type 100 silicon wafer with a resistivity of 3.38–4.65 O cm was used for the fabrication of the oscillator. Using this technology, it is possible to fabricate sensor and oscillator for the WSS concurrently. The technology has been used for fabrication of devices such as sensors and circuits in our group. The proposed ring oscillator was fabricated by 2.5 m m CMOS technology. Moreover, using the input PWM signal with lower duty cycle allows operating with lower power consumption. The useless power dissipation can be reduced during the OFF period of the input PWM signal. The proposed oscillator is operated in ON period of the input PWM signal due to NAND logic of the oscillator. However, the proposed oscillator does not need the switch device as shown in Fig. Then, the controlled carrier is transferred to antenna by the switch device such as MOS. RF transmission using conventional ring oscillator must be always turned on for switched operation as PWM signal. Using the oscillator with NAND gate, it is possible to reduce the useless power consumption because the operation of the oscillator can be controlled. For a pulse train in which the pulse duration is 1 m s and the pulse period is 4 m s, the duty cycle is 0.25 or 25%. instance, in an ideal pulse train (one having rectangular pulses), the duty cycle is the pulse duration divided by the pulse period.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2022
Categories |