• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.85-85
• /
• 2004

• 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).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.8
• /
• pp.718-729
• /
• 2015

A S / X dual broad band patch antenna with shared aperture structure is fabricated. A $2{\times}2$ perforated patch is used for S-band operation and a $2{\times}2$ patch antenna array is integrated in the $2{\times}2$ perforation for X-band operation. The measurement results of a S / X dual broad band patch antenna with shared aperture structure show the broad band characteristics larger than 20 % in both bands.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2005.11a
• /
• pp.371-374
• /
• 2005

This paper presents the design and fabrication of a cost effective and broad band 8$\times$8 stacked patch array antenna which are backed by a metal cavity operating at 400Hz based on 4 layers LTCC technology. Gain of antenna can be enhanced by using a metal cavity, which can be easily implemented by using LTCC substrates and vias. The broadband performance can be obtained by varying the dimension of patch and the number of layers. Furthermore, to keep the feeding network as smal1 as possible and reduce radiation from feeding network a mirrored patch orientation and embedded micro strip line are adopted, The fabricated antenna is $40\times45\times0.4$ $mm^3$in size. It shows gain 20.4dBi, beam width 10.7deg and impedance bandwidth of l0dE return loss 3.35GHz (40.9$\sim$44.25 GHz), which is about 8% of a center frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.5
• /
• pp.748-754
• /
• 2000

A novel single feed wide band CP stacked microstrip antenna using crossed slots has been designed, fabricated and measured. For the single rediating element the designed 10dB return loss bandwidth is 34.5%99.45~13.54 GHz), 3dB axial ratio bandwidth is 18.7%(11.17~13.39GHz), and 6 dB gain bandwidth is 29%(10.21~13.64GHz). For the 2$\times$2 array designed using a sequential rotation method, the 10dB return loss bandwidth is 35.9%(9.69~13.94GHz), 3dB axial ratio bandwidth is 34.6GHz (9.93~14.03GHz), and 6dB gain bandwidth is 27.4%(10.35~13.6GHz). For the fabricated 8$\times$8 array antenna, the 10dB return loss bandwidth is 27.3%(10.17~13.41GHz), 3dB axial ratio bandwidth is 27.9GHz(10.1~13.4GHz), and the radiation pattern is good agreement with theory. This antenna can be used for broadband applications for communications or broadcasting in Ku band.

• Journal of electromagnetic engineering and science
• /
• v.10 no.4
• /
• pp.309-315
• /
• 2010

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with $\varepsilon_r$=2.2 and three different thicknesses of 0.253 mm, 0.508 mm and 0.762 mm) are integrated to provide simultaneous operation at S band (3~3.3 GHz) and X band (9~11 GHz). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR$\leq$2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 dB. The measured cross-polarization level is ${\leq}-21$ dB for the S-band and ${\leq}-20$ dB for the X-band.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.7
• /
• pp.81-88
• /
• 2004

In case of mechanical down tilting, a horizontal pattern is distorted and beam width widens whenincreasing tilt angle, which causes an expansion of hand off region and burden base station equipment. In contrast, electrical down tilting has advantage that horizontal HPBW is kept constant with down tilting. In this paper, based on a phased array technology, dual polarized base station antenna with electrical down tilting was developed at 800MHz band. The antenna has down tilting range of 0$^{\circ}$ to 14$^{\circ}$, and 15㏈i gain. We use stacked microstrip patch as a radiated element and apply balanced feed technique to improve isolation between ports and discrimination of cross polarization. The effect of electrical down tilting was verified by field test.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.12
• /
• pp.1325-1332
• /
• 2009

In this paper, we design a 2.4 GHz bio-radar system that can detect human heartbeat and respiration signals with small size and improved noise performance using single circular-polarized antenna and phase-locked loop. The demonstrated bio-radar system consists of single circular-polarized antenna with $90^{\circ}$ hybrid, low-noise amplifier, power amplifier, voltage-controlled oscillator with phase-locked loop circuits, quadrature demodulator and analog circuits. To realize compact size, the printed annular ring stacked microstrip antenna is integrated on the transceiver circuits, so its dimension is just $40\times40mm^2$. Also, to improve signal-to-noise-ratio performance by phase noise due to transmitter leakage signal, the phase-locked loop circuit is used. The measured results show that the heart rate and respiration accuracy was found to be very high for the distance of 50 cm without the additional digital signal processing.