Pakasiri, Chatrpol

Preferred name

Pakasiri, Chatrpol

Alternative Name

Pakasiri, Charpol

Main Affiliation

Integrated Innovative Technology

chatrpol.pa@kmitl.ac.th

Now showing 1 - 10 of 26

Some of the metrics are blocked by your
consent settings
Modified Class-F power amplifier design with fundamental frequency output impedance load
(2021-04-01)
Pakasiri, Chatrpol
;
Manasummakij, Prateep
;
Wang, Sen
A modified Class-F power amplifier with medium output power at 433 MHz was designed, simulated and implemented in this paper. The design process used a load condition of 1) output impedance of the amplifier at the fundamental frequency, 2) short-circuit loads at the even harmonics and 3) open-circuit loads at the odd harmonics. By biasing the circuit to be a typical Class-F, the circuit yielded moderate efficiency as the load condition was different from the optimum one. By strongly biasing the circuit toward that of Class-A, the load condition approached the optimum, but the circuit still yielded moderate efficiency due to the low efficiency nature of a Class-A amplifier. By proper choice of the operating point in Class-AB, a prototype circuit, with 9 dBm input power, yielded a maximum PAE of 68.5% with output power 21.8 dBm. Furthermore, at 11 dBm input power, the prototype yielded a better PAE 79.6% with 23.2 dBm output power. Our design procedure did not need expensive load-pull equipment.
Some of the metrics are blocked by your
consent settings
Compact Wilkinson Power Divider Using Composite Right/Left-Handed Transmission Line on CMOS Process
(2020-03-01)
Nithiporndecha, Kittipong
;
Wang, Sen
;
Pakasiri, Chatrpol
This paper shows the design and analysis of CMOS Wilkinson power divider using composite right/left-handed transmission lines. The effects of lossy components in the circuit are also analyzed. The circuit is then implemented on a 0.18-μm CMOS process. The return losses are less than -16 dB, the isolation is better than -26 dB, and the insertion losses are better than -5.15 dB at the frequencies of interest. Its chip size is 0.5 mm2 (9.9e-5λ<inf>o</inf>2) including testing pads.
Some of the metrics are blocked by your
consent settings
Impedance Extraction using Impedance Perturbation Method of Electrically Small HF Loop Antenna with Undercover Ferrite Sheet
(2018-12-24)
Mangmisirisap, Kanthiphat
;
Bandudej, Kamorn
;
Pakasiri, Chatrpol
Electrically small high frequency (HF) loop antenna with undercover ferrite sheet yields high radiation resistance for multi-Turn structure. Antenna impedance without radiation differs greatly from that with the radiation effect. Impedance perturbation method is used for extracting antenna impedance with radiation effect at a desired frequency. Matching networks are designed based on the extracted antenna impedance. The measurement results show that the antenna with the designed matching network provides higher return loss.
Some of the metrics are blocked by your
consent settings
Improvement of transmission line circuit on lossy substrate with application on phase shifter design
(2019-03-01)
Pakasiri, Chatrpol
;
Kongchayasukwat, Thitipun
Lumped transmission line circuit design on lossy substrate is studied in this paper. Conventional single section lumped transmission line cannot perform well on lossy substrate as its electrical length gets longer. Multi-section transmission lines can be used to improve transmission line properties in this case. Phase shifter circuits are designed with a large electrical length transmission line. By using a multi-section transmission line, the resulting transmission line properties are better than those of single section transmission line.
Some of the metrics are blocked by your
consent settings
Wireless power transfer system design using electrically small HF loop antennas
(2019-03-01)
Mangmisirisap, Kanthiphat
;
Bandudej, Kamorn
;
Pakasiri, Chatrpol
Wireless power transfer system design with inductive power transfer is proposed in this paper. The system input and output impedances are extracted by using impedance perturbation method. Using matched capacitors, the measured system reflection coefficient magnitude at 13.56 MHz is as low as 0.04 and the transmission coefficient magnitude is at 0.95.
Some of the metrics are blocked by your
consent settings
Study performance of near-field HF antenna using undercover ferrite sheet
(2017-10-19)
Kankhunthod, Kittipon
;
Pakasiri, Chatrpol
A planar loop antennas with and without undercover ferrite are studied in this paper. The field simulated results show that the antenna with undercover ferrite provides more magnetic flux density at the same distance away from it. Using a receiving loop antenna in the simulation, the power gain of both transmitting antennas is compared. By using proper matching networks, the planar loop antenna with undercover ferrite provides a better power gain than that of the planar loop antenna.
Some of the metrics are blocked by your
consent settings
A Compact 0.73~3.1 GHz CMOS VCO Based on Active-Inductor and Active-Resistor Topology
(2024-06-01)
Pakasiri, Chatrpol
;
Hsu, Ke Chung
;
Wang, Sen
In this paper, a wideband VCO that covers popular Long-Term Evolution (LTE) 0.7 GHz and LTE 2.6 GHz frequencies is designed and developed in a standard 0.18 μm CMOS process. The VCO utilizes active inductors to achieve coarse-tuning of the inductance and a compact chip area. Moreover, an active feedback resistor is introduced into the active inductor for fine-tuning of the inductance. The feedback resistor also affects the equivalent resistance of the active inductor; therefore, wide inductance tuning and low power consumption can be obtained by optimizing the resistor. The core area of the fabricated CMOS chip is merely 0.046 mm2, excluding all testing pads. With a 6.7~10.1 mW DC consumption, the measured oscillation frequencies range from 0.73 GHz to 3.1 GHz, which demonstrates a 123.8% tuning range. At the frequencies of interest, the measured phase noises are from −80.7 to −84.5 dBc/Hz at a 1 MHz offset frequency.
Some of the metrics are blocked by your
consent settings
A 10 GHz Compact Balun with Common Inductor on CMOS Process
(2023-01-01)
Pakasiri, Chatrpol
;
Xu, Jian Long
;
Wang, Sen
This paper presents a compact balun with a common inductor design. The design used Wilkinson-type balun topology with modified lumped transmission lines and a common inductor to realize circuit size reduction on a lossy CMOS process. Measurements of the prototype chip had a reflection coefficient below 17.8 dB at all ports, an insertion loss of 1.98 dB, and an isolation of 16.8 dB. The chip size was only 0.025λ<inf>0</inf> × 0.034λ<inf>0</inf>.
Some of the metrics are blocked by your
consent settings
A millimeter-wave in-phase gate-boosting rectifier
(2014-11-01)
Wang, Yu Jiu
;
Liao, I. No
;
Tsai, Chao Han
;
Pakasiri, Chatrpol
This paper introduces a new class of RF-to-dc rectifiers called the in-phase gate-boosting rectifier (IGR). An IGR utilizes an in-phase passive voltage multiplier (IPVM) to boost in-phase V<inf>\rm GS</inf> swing from the driving V<inf>\rm DS</inf> swing. This design simultaneously reduces the effective threshold voltage, forward resistance, and the reverse leakage current of the rectifying transistor. As a consequence, the sensitivity and the efficiency of a high-frequency rectifier can be improved. Furthermore, a C<inf>G</inf>-loaded IPVM presents low input conductance and is shunted with the drains/sources of the rectifying transistors. This makes the realization of the input matching network between the IGR core and the antenna easier, and achieves a higher voltage swing at the input terminals of the IGR core. The criteria, properties, and relating proofs of the IPVM are also discussed. A differential seven-stage millimeter-wave IGR is implemented in a 65-nm RF CMOS process. In this design, an interleaving internal threshold cancellation bias scheme is also introduced to further suppress the power consumption due to biasing circuitry without increasing the layout area. The implemented integrated circuit achieves a state-of-the-art - 7-dBm sensitivity with 20% peak efficiency at 53 GHz and a bandwidth of 10 GHz from 46 to 56 GHz.
Some of the metrics are blocked by your
consent settings
2.4 GHz Rat-Race Coupler with Complex Termination on IPD Process
(2018-12-24)
Pakasiri, Chatrpol
;
Wang, Sen
This paper proposed a rat-race circuit implement on IPD (Integrated Passive Device) process. The termination loads of the circuit have a complex impedance value. Design equations for single frequency operation of distributed structure are provided. Lumped components representation of distributed structure is illustrated in the design example. The measured results yield-5.6 dB reflection coefficient at the input port and-14 dB transmission coefficient at the isolation port. The transmission coefficients at the output ports are better than-7 dB while the phase difference is less than 2 degrees.

Pakasiri, Chatrpol

Filters

Settings

Sort By

Results per page