GaAs pHEMT Technology Supports High Power, High Efficiency, and High-Frequency Applications
Key Takeaways
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GaAs devices provide high efficiency, excellent linearity of the amplifier, and cost-effectiveness.
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The dielectric constant and the semi-insulating property of GaAs make it suitable for microstrip or coplanar waveguide designs in MMICs.
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The high yield, reproducibility, and small size of GaAs pHEMT technology-based MMICs make them a constant component in automotive radar, microwave communication, and millimeter wave imaging applications.
GaAs is the material that makes high-frequency RF, microwave, and millimeter wave communication a reality.
When targeting wireless communications above 100GHz, GaAs pHEMT technology-based devices should not be neglected. GaAs pHEMT technology-based devices can be incorporated in circuits such as power amplifiers, low-noise amplifiers, and wide-bandwidth modulators. This technology exhibits better performance than its predecessors, GaAs FETs and GaAs MESFETs.
Let’s learn more about GaAs pHEMT technology.
GaAs Semiconductor Applications
In the last two decades, there has been a rapid growth in mobile communication, which has increased the demand for semiconductor materials. Apart from cellular communication, automotive radar systems and millimeter wave imaging systems have also contributed to the growth of the GaAs semiconductor market.
GaAs devices offer many advantages including high efficiency, linearity of the amplifier, and cost-effectiveness. The high power offered by GaAs power amplifiers makes them useful for monolithic microwave integrated circuits (MMICs) and modules in high-frequency communication systems.
Let’s begin with an overview of the various GaAs semiconductor technologies.
GaAs-Based Microwave Semiconductor Technology
GaAs is the material that makes high-frequency RF, microwave, and millimeter wave communication a reality. The amplification of high-frequency microwave signals was tedious before the development of GaAs MESFETS. With GaAs MESFET technology, MMICs are fabricated and the frequency application is extended to 100s of GHz.
The dielectric constant and the semi-insulating property of GaAs make it suitable for microstrip or coplanar waveguide designs in MMICs. The operating temperature of the device channel can be about 150°C, and this high channel temperature makes the GaAs material-based device suitable for high-temperature operations.
However, the fabrication costs of GaAs MESFET technology-based MMICs is almost equal to that of silicon devices. New GaAs material showcases higher performance than GaAs MESFETs, though the cost of IC fabrication remains relatively similar.
The heterojunction bipolar transistor (HBT) technology developed in GaAs semiconductor material ICs is used in ultra-high frequency to the C-band frequency range.
pHEMT Technology
Pseudomorphic high electron mobility transistors (pHEMTs) are the MMIC technology used for manufacturing microwave integrated circuits. The pHEMT technology-based MMICs are popular among microwave electronics enthusiasts, as they provide wideband performance characteristics such as low noise generation, high amplifier linearity, and high reliability at high-frequency operation. The pHEMT technology showcases outstanding high-frequency operation due to the presence of heterojunction and different band gaps in the internal structure.
The heterojunction prevents Coulomb scattering, thereby speeding up electron mobility. As different semiconductor materials are joined to form heterojunctions, it results in different types of energy bands. All these construction or fabrication peculiarities leads to the better performance of pHEMTS.
GaAs pHEMT Technology
GaAs pHEMT technology gained popularity due to its high breakdown voltage capabilities. GaAs pHEMT was the second MMIC technology and helped realize high power and high-efficiency amplifiers of low noise figures. GaAs pHEMT technology is the most promising commercial solution for RF, microwave, and millimeter-wave applications.
The high yield, reproducibility, and small size of GaAs pHEMT technology-based MMICs make them a constant component in automotive radar, microwave communication, and millimeter wave imaging applications.
Advantages of GaAs pHEMT Technology
The advantages of GaAs pHEMT technology include:
- High electron mobility
- High-frequency operation
- High temperature operation
- High breakdown voltage of around 16V
- Excellent efficiency and power
GaAs pHEMT Technology-Based MMIC Applications
Let’s discuss some specific applications of GaAs pHEMT technology-based MMICs.
Wide-Band MMIC Power Amplifiers
GaAs pHEMT technology-based wideband MMIC power amplifiers are significant at high frequencies, as they improve the flat small signal gain, maximum power added efficiency, and minimum saturated output power. The power density performance of GaAs pHEMT technology MMICs is the industry's best when compared with other MMIC technologies.
Dual Gate Devices Based on GaAs pHEMT Technology
In pHEMTs, materials such as AlGaAs, InGaAs, or GaAs are alternately used. In certain double-doped pHEMTS, the Al or invariants of GaAs are epitaxially grown on the semi-insulating GaAs wafer. In millimeter-wave applications, dual-gate GaAs pHEMT technology-based devices are used. Dual gate GaAs pHEMT technology devices give superior gain at large gate widths compared to single-gate devices. The frequency of operation is also in the 100s of GHz.
Cadence can help design HEMT or pHEMT-based MMICs for power amplification. Cadence circuit design software can assist you in developing GaAs pHEMT technology-based MMICs for various applications such as microwave communication and automotive radar systems. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.