الفهرس 
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Abstract
Recently, designing broadband or wide-band matching networks has become
more desirable in analyzing and implementing a microwave transistor amplifier as a
low noise amplifier, which is also required to achieve good performance, such as
gain flatness and low noise figure. The Low Noise Amplifier (LNA) is an essential
block at the receiving end of any wireless communication system. As a result, the
broadband LNA has a distinct design that enables it to resolve a variety of
challenges, such as broadband matching to reduce the reflection coefficient at the
input, flat and appropriate gain, low noise figure, and high linearity, which is
challenging to have good noise performance with flat gain simultaneously.
Furthermore, it should attain a high flat gain to prevent noise from later stages. As
the development for achieving such stated difficulties in designing broadband LNA,
new LNA topologies and design approaches have become one of the most exciting
issues in radio frequency system design.
This thesis mainly focuses on introducing a high flat gain Broadband Low
Noise Amplifier (LNA) design approach, which is based on using a Real Frequency
Technique (RFT) as new solving methodology for this interesting research area.
Firstly, the broadband matching networks has been designed with second-order LC
lumped elements to maintain the Noise Figure (NF) minimum as possible and to
maximize the Transducer Gain (GT) based on selecting the optimum (ZS, ZL) LNA
terminations that have been used over a 2.1-4.2 GHz. The design has demonstrated
a high stable gain in the range of 19.19 –18.73 dB with ± 0.2 dB gain flatness over
the specified band. Moreover, the NF has been obtained at 0.68 – 0.82 dB and a
stable operation throughout a broad bandwidth.
Furthermore, the proposed method results have been compared with an
analytical methodology which is based on computing equivalent input and output
circuits for the transistor model using its scattering parameters. For the verification
purpose, the performances of the synthesized amplifier are compared using the
MATLAB platform and ADS simulation software. The output results have a good
agreement with the proposed method outcomes, which makes this method a new
promising technique for the high flat gain broadband LNA design utilized in
3G/4G/5G wireless receiver systems. Based on the results of the RFT that give more gain flatness than the analytical
approach, the implementation of broadband LNA is achieved by converting the
lumped component to distributed elements using Microstrip Transmission Line
(MSTL). The performance of the designed LNA proposed circuit, after converting
to MSTL, has been simulated to achieve a high gain of 17.98dB and gain flatness of
±0.39; the input return loss S11 varied between -12.4 dB and -20.07 dB. The noise
figure (NF) achieved a good result of 0.76 dB - 0.89 dB over the desired frequency
range.
Finally, the layout and EM simulation were performed for implementing the
proposed LNA. Due to the carrying of EM simulation and the parasitic loss that is
added by the lumped elements of bias and stability circuits, the results will be
affected by these factors. However, the performed optimization has achieved a close
agreement with the schematic outcomes. The obtained power gain is high with a
value of 19.6 dB and flatness of ±0.8 dB. The value of the input reflection coefficient
is less than -6 dB which varied from -20.31 dB to -8.75 dB, and the NF of 0.97 dB
at the central frequency of 3.2 GHz.
The research is categorized into three main chapters; the first one, the
introduction, includes basic information about the thesis topics, such as low noise
amplifier parameters and applications; and we present numerous techniques of
broadband amplification approaches. Finally, we conclude the chapter with the
thesis’s aims and objectives.
In the second chapter, we outline a review of previous research for the
proposed wireless application.
The third chapter discusses the experimental technique used in such an
investigation. We provide all processes for our design and a comparison to previous
works in our bandwidth that used alternative methodologies In the fourth chapter, we explore the structure results of our design for
implementing the broadband LNA and its layout. In addition, we included the
measurement setup for our design fabrication.