• JSTS:Journal of Semiconductor Technology and Science
• /
• v.9 no.4
• /
• pp.192-197
• /
• 2009

This paper presents the design and measurement of a 2.4/5.2-GHz dual band VCO with a balanced frequency doubler in $0.18\;{\mu}m$ CMOS process. The topology of a 2.4 GHz VCO is a cross-coupled VCO with a LC tank and the frequency of the VCO is doubled by a frequency balanced doubler for a 5.2 GHz VCO. The gate bias matching network for class B operation in the balanced doubler is adopted to obtain as much power at 2nd harmonic output as possible. The average output powers of the 2.4 GHz and 5.2 GHz VCOs are -12 dBm and -13 dBm, respectively, the doubled VCO has fundamental harmonic suppression of -25 dB. The measured phase noises at 5 MHz frequency offset are -123 dBc /Hz from 2.6 GHz and -118 dBc /Hz from 5.1 GHz. The total size of the dual band VCO is $1.0\;mm{\times}0.9\;mm$ including pads.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.5
• /
• pp.393-396
• /
• 2018

Herein, a 94-GHz low-noise amplifier (LNA) using the 65-nm CMOS process is presented. The LNA is composed of a four-stage differential common-source amplifier and impedance matching is accomplished with transformers. The fabricated LNA chip shows a peak gain of 25 dB at 94 GHz and has a 3-dB bandwidth at 5.5 GHz. The chip consumes 46 mW of DC power from a 1.2-V supply, and the total chip area, including the pads, is $0.3mm^2$.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.4
• /
• pp.886-893
• /
• 2004

In this paper, active resonator oscillator using active band pass filter with gain, active resonator with negative resistance using transistor(agilent ATF-34143) is designed and fabricated. Proposed active resonator oscillator for local oscillator in ISM band(5.8GHz) is designed with 5.5 GHz oscillation frequency. Designed active resonator oscillator implemented on the substrate which has the relative dielectric constant of 3.38, the height of 0.508mm, and metal thickness of 0.018mm. Active resonator oscillators using active band pass filter with gain show the oscillation frequency of 5.6GHz with the output power of -2dBm and phase noise of -81dBc/Hz at the offset frequency of 100kHz. Active resonator oscillators active resonator with negative resistance show the oscillation frequency of 5.6, 5.8GHz with the output power of -4dBm and phase noise of -91dBc/Hz at the offset frequency of 100kHz.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.4A
• /
• pp.312-319
• /
• 2005

In this paper, a meander-type microstrip patch antenna for application in 5GHz-band is designed and fabricated. To obtain enough bandwidth in VSWR<2, the foam is inserted between substrate and ground plane, the coaxial probe source is used. Antenna is simulated varing the length and width of meander line, the position of probe feeding and the thick of airgap. Later anterlna is fabricated with optimizated antenna parameter. The measured result of Fabricated antenna obtained $1GHz(17.5\%)$ bandwidth in VSWR<2$, the gain of $.3\sim9.5$dBi, Unidirectional pattern.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.8
• /
• pp.52-58
• /
• 2008

Ths paper describes the Dual-band switch which was proposed new structure that could improved the specification of broadband and designed by the optimized structure through simulation. The Dual-band switch with 2.4[GHz]/5.8[GHz] that can apply to 802.11a/b/g system that is commercialized present was studied to get a new structure with higher power, high isolation. The transmitter of switch was designed to operate a parallel switching element with stack structure of two FET. The receiver designed to have asymmetry structure that insert series FET in addition to basic serial/parallel FET. SPDT(Single Pole Double Throw) Tx/Rx FET switch is a device that can do switching from a port of input to two port of output. The fabricated SPDT switch has the characteristic of insertion loss of a below -3[dB] form DC to 6[GHz] and the isolation of a below -30D[dB](Rx mode).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5827-5831
• /
• 2011

In this paper, 5Ghz microstrip patch antenna for wireless LAN is designed, fabricated, and measured. To obtain wide bandwidth and high gain, antenna parameters such as patch size(W, L), the length of the slot(C), and the slot width(D) are simulated by HFSS(High Frequency Structure Simulator). From these parameters optimized, the microstrip patch antenna is fabricated using FR-4 substrate. The measured results of the antenna are as follows: The center frequency of 5.2 GHz, insertion loss of -41.17dB, bandwidth of 258MHz, and VWSR of 1.1.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.2
• /
• pp.37-44
• /
• 2008

This paper presents a 5.8 GHz PLL using high-speed ring oscillator for WLAN. The proposed ring oscillator has been designed using the negative skewed delay scheme and for differential mode operation. Therefore, the oscillator is insensitive to power-supply-injected noise, and it has the merit of low 1/f noise because tail current sources are not used. The output frequency ranges from 5.13 to 7.04 GHz with the control voltage varing from 0 to 1.8 V. The proposed PLL circuits have been designed, simulated, and proved using 0.18 um 1.8 V TSMC CMOS library. At the operation frequency of 5.8 GHz, the locking time is 2.5 us and the simulated power consumption is 59.9 mW.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.2
• /
• pp.83-90
• /
• 2000

In this paper, a stacked circular-disk microstrip 1${\times}$4 array antenna was designed and manufactured and tested to apply in next generation mobile communication, on IMT-2000 system(up-link: 1.885 GHz∼2.025 GHz, down-link: 2.11 GHz∼2.2 GHz) base station which has dual frequency, broadband and high-gain characteristics. The experimental results are as follows : resonant frequency of 1.885 GHz and 2.178 GHz VSWR (1.064 , 1.432), return loss (-30.19 dB , -24.99 dB), band width (VSWR<2) are 402 MHz, -3dB beam width at radiation pattern are ${\alpha}$E-16.8$^{\circ}$, ${\alpha}$H-69$^{\circ}$(1.885 GHz) and ${\alpha}$E-l5.2$^{\circ}$, ${\alpha}$H-51.5$^{\circ}$(2.178 GHz), gain(13.7 dBi∼15.21 dBi).

• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1611-1618
• /
• 2017

This paper presents a compact reconfigurable printed monopole antenna, operating in three different frequency bands (2.45 GHz, 3 GHz and 5.2 GHz), depending upon the state of the lumped element switch. The proposed multiband reconfigurable antenna is designed and fabricated on a 1.6 mm thicker FR-4 substrate having a relative permittivity of 4.4. When the switch is turned ON, the antenna operates in a dual band frequency mode, i.e. WiFi at 2.45 GHz (2.06-3.14 GHz) and WLAN at 5.4 GHz (5.11-5.66 GHz). When the switch is turned OFF, it operates only at 3 GHz (2.44-3.66 GHz). The antenna radiates omni-directionally in these bands with an adequate, bandwidth (>10 %), efficiency (>90 %), gain (>1.2 dB), directivity (>1.7 dBi) and VSWR (<2). The fabricated antenna is tested in the laboratory to validate the simulated results. The antenna, due to its reasonably compact size ($39{\times}37mm^2$), can be used in portable devices such as laptops and iPads.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.9 s.112
• /
• pp.874-882
• /
• 2006

We surveyed the international and national spectrum & technical standardization trends of extremely adaptive frequency bands $57\sim64GHz$ that can provide 1 Gbps bit-rate ultra broadband service in above 30 GHz millimeter waves, and analyzed service scenarios and the characteristics of these bands, As a result of these analysises, 1 Gbps ASK channel bandwidth needs 2.5 GHz and total bandwidth calculated 7 GHz for dual FDD. finally, we proposed the nationally suitable allocation plan of millimeter wave bands $57\sim64GHz$.