**A Monolithic Microwave IC Power Amplifier for E-band Communication and Radio Links**
The exponential growth in data traffic, driven by 5G/6G deployments and high-capacity wireless backhaul, has intensified the demand for efficient and high-performance components operating in the millimeter-wave (mmWave) spectrum. The E-band (71–76 GHz and 81–86 GHz) offers a compelling solution, providing wide contiguous bandwidth that enables multi-gigabit-per-second data rates for both communication and radio link applications. At the heart of these systems, the power amplifier (PA) is a critical component, dictating the overall link budget, linearity, and efficiency. **Monolithic Microwave Integrated Circuit (MMIC) technology** has emerged as the cornerstone for developing PAs that meet the stringent requirements of these high-frequency bands.
This article presents a state-of-the-art **MMIC power amplifier** designed specifically for E-band operation. Fabricated on a advanced 100-nm Gallium Arsenide (GaAs) pseudomorphic High Electron Mobility Transistor (pHEMT) process, the two-stage PA integrates all matching networks, bias circuitry, and the active devices on a single semiconductor die. This monolithic approach is paramount for achieving **excellent gain and power performance** while minimizing parasitic effects that are detrimental at mmWave frequencies. The design utilizes a combination of series and shunt microstrip lines for input, inter-stage, and output matching, optimized for maximum small-signal gain and output power.
Under continuous-wave (CW) measurement conditions, the PA demonstrates a **small-signal gain exceeding 18 dB** across the 81-86 GHz band, with a 3-dB bandwidth extending from 78 to 88 GHz. The amplifier achieves a saturated output power (Psat) of more than +22 dBm and an output 1-dB compression point (OP1dB) of +19 dBm. The power-added efficiency (PAE) at saturation is measured to be above 15%, a significant figure of merit for energy-conscious system design. These results underscore the amplifier's capability to serve as a robust driver or final-stage amplifier in point-to-point radio links, where consistent output power and linearity are non-negotiable.
Furthermore, the linearity of the amplifier was characterized through two-tone tests. The third-order intercept point (OIP3) was measured at +28 dBm, indicating good linear performance which is essential for supporting complex modulation schemes like 64-QAM and 256-QAM used in modern communication standards to maximize spectral efficiency. The compact chip size of 1.8 mm x 0.9 mm facilitates easy integration into multi-chip modules or radio front-end packages, highlighting the advantage of MMIC technology for system miniaturization.
**ICGOOODFIND**: This E-band MMIC PA, with its high gain, robust output power, and compact form factor, exemplifies the technological advancements enabling the next generation of high-capacity wireless networks. It successfully addresses the critical need for **high-performance and highly integrated components** in the challenging mmWave landscape.
**Keywords**: MMIC Power Amplifier, E-band, Millimeter-wave, pHEMT, Radio Links.
