• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.54-61
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• 2007

A variable gain low noise amplifier (VG-LNA) implemented in TSMC 0.18 um process is presented. This VG-LNA is designed of two stage amplifier, and its gain is controlled by the shunt feedback loop composed of a gain control transistor (GCT) and a coupling capacitor in second stage. The channel resistance of GCT in the shunt feedback loop influences the input and output stages of a second stage by the Miller effect. Total gain of the proposed VG-LNA is changed by two factors, the load impedance reduction and the interstage mismatch by controlling the channel resistance of the GCT. Consequently, by adding a shunt feedback with a gain control transistor, this proposed VG-LNA achieves both wide gain tuning range of 37 dB and continuous gain control simultaneously.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.90-95
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• 2014

This paper presents a VHF/UHF-band variable gain low noise amplifier for multi-standard mobile TV tuners. A proposed VHF-band variable gain amplifier is composed of a resistive shunt-feedback low noise amplifier to remove external matching components, a single-to-differential amplifier with input PMOS transcoductors to improve low frequency noise performance, a variable shunt-feedback resistor and an attenuator to control variable gain range. A proposed UHF-band variable gain amplifier consists of a narrowband low noise amplifier with capacitive tuning to improve noise performance and interference rejection performance, a single-to-differential with gm gain control and an attenuator to adjust gain control range. The proposed VHF-band and UHF-band variable gain amplifier were designed in a $0.18{\mu}m$ RF CMOS technology and draws 22 mA and 17 mA from a 1.8 V supply voltage, respectively. The designed VHF-band and UHF-band variable gain amplifier show a voltage gain of 27 dB and 27 dB, a noise figure of 1.6-1.7 dB and 1.3-1.7 dB, OIP3 of 13.5 dBm and 16 dBm, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.66-69
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• 2016

In this paper, we suggests a Ka-band LNB considering next-generation UHD satellite TVRO. Since Ka-band has grater attenuation than Ku-band in atmosphere, we designed the low-noise down-converter to improve receiving sensitivity and to extend a dynamic range of receiver. It aims to compensate a quality of ultra high definition transmission signal for rainfall. The low-noise block diagram consists of a three-staged amplifier (LNA), band-pass filter for deleting image (BPF), mixer and IF when considering nonlinear characteristics in the receiver RF front end module. Also, we showed a LNB through optimization processes affecting dynamic range directly in receiver FEM. Asa resuly of experiment, the gain of low-noise down-converter show between 58.5dB and 60.7dB, the noise figure has a high characteristic as 1.38dB. Finally, the phase noise of local oscillator is -63.10dBc at 100MHz offset frequency.

• Journal of Advanced Navigation Technology
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• v.6 no.2
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• pp.113-118
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• 2002

In this paper, an internal GPS antenna for mobile phones is designed and fabricated. For the miniaturization of the antenna, high permittivity dielectric substrate((${\varepsilon}_r$=90) and small ground plane ($13mm{\times}13mm$) are used. To increase the receive gain, the antenna is composed with LNA(Low Noise Amplifier). Results of the manufactured antenna($13mm{\times}13mm{\times}8mm$) show that the maximum antenna gain is about 12 dBi, the axial ratio is less than 3 dB, and the current consumption of LNA is less than 4 mA.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.38-46
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• 1999

o.25${\mu}m$ T-shaped gate P-HEMT is fabricated and used for design of X0band three stage monolithic microwave integrated circuit(MMIC) low noise amplifier(LNA). The fabricated P-HEMT exhibits an extrinsis transconductance of 400mS/mm and a drain current of 400mA/mm. The RF and noise characteristics show that the current gain cut off frequency is 65GHz and minimum noise figure(NFmin) of 0.7dB with an associated gain of 14.8dB at 9GHz. In the design of the three stage LNA, we have used the inductive series feedback circuit topology with the short stub. The effects of series feedback to the noise figure, the gain, and the stability have been investigated to find the optimal short stub length. The designed three staage LNA showed a gain of above 33dB, a noise figure of under 1.2dB, and ainput/output return loss of under 15dB and 14dB, respectively. The results show that the fabricated P-HEMT is very suitable for a X-band LNA with high gain.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.11
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• pp.1055-1063
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• 2013

Low noise amplifiers(LNAs) are an integral component of RF receivers and are frequently required to operate at wide frequency bands for various wireless systems. For wideband operation, important performance metrics such as voltage gain, return loss, noise figures and linearity have been carefully investigated and characterized for the proposed LNA. An inductive shunt feedback configuration is successfully employed in the input stage of the proposed LNA which incorporates cascaded networks with a peaking inductor in the buffer stage. Design equations for obtaining low and high input matching frequencies are easily derived, leading to a relatively simple method for circuit implementation. Careful theoretical analysis explains that poles and zeros are characterized and utilized for realizing the wideband response. Linearity is significantly improved because the inductor between gate and drain decreases the third-order harmonics at the output. Fabricated in $0.18{\mu}m$ CMOS process, the chip area of this LNA is $0.202mm^2$, including pads. Measurement results illustrate that input return loss shows less than -7 dB, voltage gain greater than 8 dB, and a little high noise figure around 7~8 dB over 1.5~13 GHz. In addition, good linearity(IIP3) of 2.5 dBm is achieved at 8 GHz and 14 mA of current is consumed from a 1.8 V supply.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1121-1129
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• 2009

In this paper, the UWB(Ultra-Wide Band) modules such as a pulse generator and the LNA(Low-Noise Amplifier) with AGC(Auto Gain Control) are designed to construct a cross-borehole pulse radar system, of which performance is compared with the existing system. The budget and specification of the radar system are determined by calculating the total path loss of the underground medium including an empty cavity. The pulse generator is fabricated to have the repeatation frequency 40 kHz, the pulse width lower than 5 ns and the peak signal level +73 dBm. The UWB LNA is designed to have the noise figure 3.77 dB, the variable gain range 100 dB and the frequency range of 20 MHz to 200 MHz. Compared with the existing system in an actual test site, the implemented system renders it possible to detect the blind area due to the UWB LNA with low noise figure.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.9
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• pp.13-20
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• 1999

A 2-stage MMIC(monolithic Microwave Integrated Circuits) LNA(Low Noise Amplifiers) at 30GHz hand has been designed and fabricated for the Ka-band Satellite Communications. The $0.15 {\mu}m$ with the width of $80 {\mu}m$ pHEMT technology was used for the fabrication of this MMIC LNA. Using the series feedback technique, ultra low noise and excellent S11 could be obtained at the same time without the cost of gain at 30GHz-band. The stability factors(Ks) for each stage and overall stage are greater than 1 at full frequency bands by the bias circuits and stabilization circuit. The measured performances, which agree well with the predicted performances, show this 2-stage MMIC LNA has the gain of more than 15.7dB and noise figure of less than 2.09dB over 29GHz to 33GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.69-73
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• 2002

We have designed and fabricated a low-cost, V-band CPW receiver chip set using GaAs PHEMT technology for the application of millimeter-wave wireless communication systems. Low noise amplifiers and down-converters were developed for this chip set. The fabricated low noise amplifier showed an S$\sub$21/ gain of 14.9 ㏈ at 60 ㎓ and a noise figure of 4.1 ㏈ at 52 ㎓. The down-converter exhibited a high conversion gain of 2 ㏈ at the low LO Power of 0 ㏈m. This work demonstrates that the GaAs PHEMT technology is a viable low-cost solution for V-band applications.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.661-665
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• 2022

The 3 MeV proton irradiation effects on SiGe low noise amplifier (LNA) (NXP BGU7005) performance under different voltage supply VCC (0 V, 2.5 V) conditions were firstly experimental studied in this present work. The S parameters including S₁₁, S₂₂, S₂₁, 1 dB compression point and noise figure (NF) of the test samples under different bias voltage supply were measured and compared before and after 3 MeV proton irradiation. The total proton irradiation fluence was 1 × 10¹⁵ protons/cm². The maximum degradation quantities of the gain S₂₁ and NF of the test samples under zero bias are measured respectively 1.6 dB and 1.2 dB. Compared with the samples under 2.5 V bias supply, the maximum degradation of S₂₁ and NF are respectively 1.1 dB and 0.8 dB in the whole frequency band. It is noteworthy that the gain and NF of SiGe LNAs under zero-bias mode suffer enhanced degradation compared with those under normal bias supply. The key influence factors are discussed based on the correlation of the SiGe device and the LNA circuit. Different process of the ionization damage and displacement damage under zero-bias and 2.5 V bias voltage supply contributed to the degradation difference. The underlying physical mechanisms are analyzed and investigated.