• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.66-75
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• 2013

The spin modulation is proposed with modulating frequency and amplitude simultaeously, and realized with the array sturcture easily located due to the nanometer size of the spintronics oscillator. In this paper, the dual-channel receiver is deisgned for detecting the spin modulated signal. Resultly, we confirmed the dual-channel recevier well detected the data sent through the spintronics oscillator array, and processed up to 200 kbps on each channel. Distance is limited up to 1 cm due to the low level signal under -60 dBm. The realized dual-channel receiver has the size of $56{\times}33mm^2$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.783-789
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• 2002

In this paper, V-band MMIC coupled oscillator arrays are presented. In the proposed array, two push-pull patch antennas are synchronized by using strong electromagnetic coupling between two antennas. As a result, total size of the array is reduced and the array can be integrated in a single chip. To verify proposed array concept, two 1$\times$2 arrays are designed and fabricated using standard 0.15 um gate length pHEMT MMIC process. The circuits are mounted in an oversized waveguide and measured. The first array shows 0.5 dBm at 56.372 GHz and the second one has an output of 5.85 dBm at 60.147 GHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.107-114
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• 2021

In this paper, a planar transistor oscillator for X-band using a newly proposed L-shaped monopole slot resonator is proposed. For planar design, an L-shaped monopole slot with an open-end is used as a resonator for a transistor oscillator. As a result of the simulated design of the resonator in three stages, a high Q value of 1169.84 and a high insertion loss of 49.934 dB were identified. The results of the final design and manufactured oscillator measurements confirmed that the oscillation output is greater than 7 dBm and has good phase noise characteristics of -58 dBc/Hz at 100 kHz offset. The proposed oscillator is planar and has the advantage of being directly applicable to microwave integrated circuit technology. It also has the advantage of being able to reduce its size as it can only be implemented in microstrip form without additional devices such as metal cavities and tuning screws in 3D structures, as in the case of a DRO (dielectric resonance oscillator).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.5
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• pp.89-96
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• 2012

In this paper, a low phase noise oscillator is designed using an interdigital hairpin resonator for UTIS (Urban Traffic Information Systems). The interdigital hairpin resonator has several characteristics compared with a conventional hairpin resonator, which are 70% size reduction and improvement of harmonic characteristics. In addition, Q (Quality factor) of the interdigital hairpin resonator is about 132, which is suitable for the design of a low phase noise oscillator. The oscillator suggested in this paper shows the output power of 12 dBm and the phase noise characteristic of -100.8 dBc/Hz at 100 kHz offset frequency from the center frequency of 5.75 GHz. The phase noise is improved by about 12 dB compared with a conventional oscillator using an interdigital hairpin resonator.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.1-5
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• 2009

In this paper, low phase noise push-push oscillator (OSC) using the metamaterial resonator for missile defense systems and satellite communication was design and implemented. The metamaterial resonator has the large coupling coefficient value, which makes a high Q value, and has reduced phase noise of OSC. The OSC with 1.8 V power supply has phase noise of -117 dBc/Hz @100 kHz in the 12 GHz. When it has been compared with metamaterial resonator and coventional spiral resonator, the reduced Q value has been -29.7 dB and -47.6 dB respectively. This low phase noise OSC using metamaterial resonator could be available to a OSC in X-band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7A
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• pp.947-954
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• 1999

A new low phase noise Dielectric Resonator Parallel Feedback Oscillator(DRPFO) that is proposed in this paper has a simple structure so that it can be fabricated in low cost and with high performance. The proposed DRPFO is in a feedback loop oscillator configuration, which is composed of a low noise amplifier, a power amplifier, a power attenuator, a power divider and a parallel resonator feedback element that consists of a dielectric resonator coupled with two microstrip lines. The measured phase noise of DRPFO was less than -81 dBc/Hz at offset frequency 1 kHz of 10.75 GHz carrier frequency, and the frequency stability of DRPFO was less than $\pm$200 kHz over the temperature range of -40$^{\circ}$C to +60$^{\circ}$C.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1175-1180
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• 2014

In this paper, the open ring type DGS(Defected Ground Structure) resonator, applicable to MMIC(Monolithic Microwave Integrated Circuit), is proposed to improve phase noise characteristics of RF oscillator. This resonator is planar type, therefore, it easy to design miniaturrized., and takes relatively high Q value. Modeling the equivalent parameter of resonator is needed, when designing the RF oscillator with resonator. The mathematical method to solve the equivalent parameter of the resonator from the measured results of resonator is introduced in this paper. To verify the method, DGS resonator with 5.8 GHz center frequency is fabricated, for measuring characteristics and calculating the equivalent parameter. The result from this process is compared with the data of the ADS simulation, and as a result both were identical.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.622-629
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• 2001

An engineering model VCO with a good phase noise for Ku-band satellite transponder is designed using a nonlinear design methodology. It generates frequencies from 1,745 and 1,755 MHz with control voltages from 0 to 5 V DC. This unit requires 7 mA of current from 5 V DC supply voltage. Phase noise characteristics of the manufactured VCO exhibit -114 dBc/Hz @10 kHz offset and -131 dBc/Hz @100 kHz of offset and its output power is 5 dBm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1386-1392
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• 2009

In this paper, we have developed the test equipment to measure performance of oscillator using Double Side Edge Trigger(DSET). This DSET increases counting number of micro pulse by frequency counter, which will successfully reduce the half measuring time to comparison with the existing counter by using DSET. This new concept of performance measuring equipment provides a high productivity and performance improvement.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.68-74
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• 2010

A sub-${\mu}$W CMOS Wien-Bridge oscillator for ultra low power (ULP) radio applications is presented. The Wien-Bridge oscillator is based on an non-inverting opamp amplifier with a closed-loop gain $1+R_2/R_1$ as a means of providing necessary loop gain. An additional RC network provides appropriate phase shift for satisfying the Barkhausen oscillation condition at the given frequency of 1/($2{\pi}RC$). In this design, we propose a novel loop gain control method based on a variable capacitor network instead of a rather conventional variable resistor network. Implemented in $0.18{\mu}m$ CMOS, the oscillator consumes only 560 nA at the oscillation frequency of 22 kHz.