• 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 Institute of Electronics Engineers of Korea TC
• /
• v.47 no.8
• /
• pp.68-73
• /
• 2010

In this paper, a compact Ultra-Wideband band-pass filter with notched band at 5.8GHz by using LC resonator is proposed. The structure of the proposed band-pass filter is very simple, and the DGS(Defected Ground Structure) is used to get the low-pass filter characteristics and the LC resonator is used to get the notched filter. The proposed band-pass filter can be much smaller than a cascaded filter type. The LC resonator is designed with a radial stub and small stub. As a result of measurement, the insertion loss is less than 0.5dB throughout the pass-band of 2.21GHz~10.92GHz, the return loss is more than 16dB and the maximum variation of group delay is 0.29ns and a notched band is 5.2GHz~6.2GHz.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.1
• /
• pp.13-18
• /
• 2015

This study presents the structure design of antenna to have the dual band characteristics in a desired frequency band through the structural modification of an antenna structure. For the experiment, a wideband crossed planar monopole antenna was used. The target frequency band was set to ISM 2.45GHz/5.8GHz. To give the properties, an additional antenna element was added to the crossed planar monopole antenna, which is a main body of the antenna. And then structural adjustment parameter was set to change the length(shape) of the antenna. Various simulations were conducted to find the dual band characteristics in the desired frequency band. The simulations brought forth the antenna bandwidth above the normal values for ISM 2.45GHz/5.8GHz. The structural adjustment parameter introduced in this study for structural modification of an antenna can be useful in developing an antenna featured with dual band(multiband) characteristics.

• 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.

• Journal of Advanced Navigation Technology
• /
• v.21 no.2
• /
• pp.193-199
• /
• 2017

In the paper, a dual band-notched monopole antenna is proposed for 2.4 GHz WLAN (2.4 ~ 2.484 GHz) and UWB (3.1 ~ 10.6 GHz) applications. The 3.5 GHz WiMAX band notched characteristic is achived by a pair of L-shaped slots instead of the previous U-shaped slot on the center of the radiating patch, whereas the 7.5 GHz band notched characteristic is achived by C-shaped strip resonator placed near to the microstrip feed line. The measured impedance bandwidth (${\mid}S_{11}{\mid}{\leq}-10dB$) is 8.62 GHz (2.38 ~ 11 GHz) which is sufficient to cover 2.4 GHz WLAN and UWB band, while measured band-notched bandwidths for 3.5 GHz WiMAX and 7.5 GHz bnad are 1.13 GHz (3.15 ~ 4.28 GHz) and 800 MHz (7.2 ~ 8 GHz) respectively. In particular, it has been observed that antenna has a good omnidirectional radiation patterns and higher gain of 2.51 ~ 6.81 dBi over the entire frequency band of interest.

• Journal of Advanced Navigation Technology
• /
• v.22 no.1
• /
• pp.31-36
• /
• 2018

In this paper, we designed and implemented an ultra wideband(UWB) antenna with band rejection characteristics. The proposed antenna consists of a planar radiation patch with slots and ground planes on both sides. Due to the slots in the radiation patch, the antenna shows band rejection characteristics. U-type slot contributes for wireless local area network(WLAN, 5.15~5.825 GHz) band rejection and n-type slot contributes for X-Band(7.25~8.395 GHz) band rejection. To make voltage standing wave ratio(VSWR) less than 2.0 for UWB frequency band except rejection bands, the shapes of planar radiation patch and ground plane was modified. The Ansoft 's high frequency structure simulator(HFSS) was used for the design process and simulations of the proposed antenna. The simulated antenna showed VSWR less than 2.0 for all UWB band excepts for dual rejection bands of 5.15 ~ 5.94 GHz and 7.02 ~ 8.45 GHz. And measured VSWR for the implemented antenna is less than 2.0 for all UWB band of 3.10~10.60 GHz excluding dual rejection bands of 5.12~5.95 GHz and 7.20~8.58 GHz.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.8
• /
• pp.549-554
• /
• 2003

In this paper, we have designed and implemented by a monolithic microwave integrated circuit(MMIC) of a 5.8GHz-band low noise amplifier (LNA) composed of receiver front-end(RFE) in a on-board equipment system for dedicated short range communication. The designed LNA is provided with two active devices, matching circuits, and two drain bias circuits. Operating at a single supply of 3V and a consumption current of 18mA, The gain at center frequency 5.8GHz is 13.4dB, NF is 1.94dB, Input IP3 is -3dBm, S$_{11}$ is -18dB, and S$_{22}$ is -13.3dB. The circuit size is 1.2 $\times$ 0.7 $\textrm{mm}^2$.>.

• Journal of the Korean Institute of Telematics and Electronics T
• /
• v.35T no.3
• /
• pp.31-36
• /
• 1998

In this paper, Image Rejection Interdigital Filter(IRIF) for 5.8GHz wireless LAN was designed and implemented. When the input signal is -30dBm in the 4~8㎓ frequency band, the insertion loss including all kinds of loss is 6.3dB in the center frequency 5.775GHz. Therefore, it was showed practically insertion loss of about -3.3dB. Especially, image signal rejection is about -l7dB in the image frequency 6.475GHz. and skirt characteristics of the high frequency band is very excellent. Therefore, it was confirmed that the proposed IRIF is suitable for RF image signal rejection in the 5.8GHz wireless LAN system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.2
• /
• pp.303-312
• /
• 2009

In this paper, we design and fabricate a disk sector antenna fed by CPW fur UWB communications. Also, we insert a rectangular slit on the arc-edge of the disk sector antenna. Then, the antenna has the directivity of E-면. In order to design the antenna, the input impedance is matched with the feed line of $50{\Omega}$ as varying the physical antenna parameters, which are the radius, the flare angle of disk sector, the length of ground, and the length of ground comer near by feed tine. Dimension of the antenna designed for UWB communication is $72mm{\times}26mm$ and bandwidth through computer simulation is $3{\sim}13GHz$. From the measured results, the bandwidth is $1.98{\sim}11GHz$. Return loss and gain of the fabricated antenna are -50.38dB, 1.34dBi at 3.5GHz, -12.27dB, 3.35dBi at 5.5GHz, -23.2dB, 3.8dBi at 8GHz and -16.17dB, 5.2dBi at 10GHz, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.14 no.6
• /
• pp.473-478
• /
• 2021

This paper designed a wideband, high gain planar trapezoidal monopole antenna using backside frequency selective surface (FSS) according to the need for wideband and high gain antenna required in various fields such as rapidly increasing wireless communication, autonomous vehicles, 5G wireless communication and wideband applications. The proposed antenna uses a dual metallic to have a structural difference from the existing FSS. By solving the complexity of the design antenna using genetic algorithms (GA) and high frequency structural simulators (HFSS) simulations, the proposed antenna is not only produce a high efficiency but also presents a wide bandwidth of 3.52 to 5.92 GHz and a gain of 10.5 dBi over the entire bandwidth, with the highest gain of 11.8 dBi at 5.1 GHz. It has been confirmed that the gain increased 8.6 dBi as the 36% impedance bandwidth of 1.8 GHz compared to the existing antenna improved to the 50% impedance bandwidth of 2.4 GHz.