gamma-gate (γ-gate)

**Gamma-Gate (Γ-Gate)** is an **asymmetric variant of the T-Gate** — where the overhanging cap extends only toward the source side, optimizing the gate-drain spacing for higher breakdown voltage while maintaining low gate resistance. **What Is a Γ-Gate?** - **Shape**: Looks like the Greek letter Γ (Gamma) in cross-section — asymmetric T with overhang toward source only. - **Advantage**: The drain side has no overhang, increasing the gate-to-drain distance ($L_{gd}$) for higher breakdown voltage. - **Application**: GaN HEMTs for power amplifiers where breakdown voltage is critical. **Why It Matters** - **Power Devices**: GaN PAs need high $V_{DS}$ (28-48V). Γ-gate maximizes breakdown without sacrificing $R_g$. - **Efficiency**: Balances high $f_{max}$ (from low $R_g$) with high output power (from high $V_{breakdown}$). - **5G/Radar**: Used in GaN MMIC designs for 5G base stations and phased-array radar. **Gamma-Gate** is **asymmetric engineering for power** — shifting the gate overhang to one side to optimize the crucial trade-off between speed and breakdown voltage.