Issue link: https://resources.system-analysis.cadence.com/i/1325428
RF Electronics Chapter 8: Amplifiers: Stability, Noise and Gain Page 275 2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0. Chapter 8 Amplifiers: Stability, Noise and Gain Introduction A few years ago, if one had to use an RF or IF amplifier, one had to design it using individual transistors and associated passive components. Now for many commercial RF frequency bands there are low cost IC's available, which perform as well or better than discrete transistor designs. For example, Analog Devices HMC8410 low noise amplifier has a 10 MHz to 10 GHz bandwidth and a noise typical figure of 1.4 dB. The Mini- Circuits PMA-5043+ is an Enhancement-mode Pseudomorphic High Electron Mobility Transistor (E-PHEMT) MMIC amplifier with a 50 MHz to 6 GHz bandwidth and a typical 0.9 dB noise figure (NF) at 2 GHz. Many other manufacturers have similar devices. Operational amplifiers with gain-bandwidth products >>1 GHz are readily available. Chapter 10 discusses the use of Operational amplifiers for RF applications in more detail. For IF amplifiers at HF frequencies it is now thus possible to use these high speed operational amplifiers, resulting in IF strips that have an excellent linearity and very low intermodulation distortion. VHF cable TV repeaters can be used for medium power amplifiers. There are also many amplifier modules available with a very high linearity, particularly for the frequency bands used by mobile phones, wireless LAN, Bluetooth and other high volume consumer frequencies. The principles for obtaining stability and low noise, outlined in this chapter, apply to any amplifier, including Microwave Monolithic ICs (MMIC) and individual BJT or FET devices, such as High Electron Mobility Transistors (HEMT). MMIC Figure 8.1. Typical Mini-Circuits MMIC circuit diagram. Several IC manufacturers like Keysight (Agilent), Mini-Circuits and NXP (Freescale Motorola), Qorvo (Triquint WJ) and others produce general purpose Microwave Monolithic Integrated Circuits (MMIC): These can be used as general-purpose amplifier blocks and can be used at frequencies from DC up to 50 GHz. RF Electronics: Design and Simulation 275 www.cadence.com/go/awr