Fig. 1. Cross-sectional structure of the dual-gate GaAs pHEMT switch.

Fig. 2. (Color online) Layout of the dual-gate GaAs pHEMT switch(125 μm × 5).

Fig. 3. Small-signal equivalent circuit of the dual-gate GaAs pHEMT switch.

Fig. 4. (Color online) Extracted parasitic capacitances versus frequency.

Fig. 5. Equivalent circuit of the GaAs pHEMT switch under the condition (V_ds = 0 V, V_gs = 0 V).

Fig. 6. (Color online) Extracted parasitic inductors versus frequency.

Fig. 7. The intrinsic part with R_G, which blocks the RF signal.

Fig. 8. (Color online) Intrinsic capacitances versus frequency for the common-gate GaAs HEMT without R_G.

Fig. 9. Equivalent circuits of the dual-gate GaAs pHEMT switch.

Fig. 10. (Color online) Comparison of the S-parameters between the simulation (-) and measurement (◇) over a frequency range of 0.1–20 GHz for a device with size of 5 × 125 μm: (a) dual-gate off state, (b) dual-gate on state, (c) triple-gate off state, (d) triple-gate on state, (e) quadruple-gate off state, and (f) quadruple-gate on state.

Fig. 11. (Color online) Illustration of the simulated and measured insertion loss and isolation (0.1–20 GHz) for a device with a size of 5 × 125 μm. (a) Insertion loss (dual-gate off state). (b) Isolation (dual-gate off state). (c) Insertion loss (triple-gate on state). (d) Isolation (triple-gate off state). (e) Insertion loss (quadruple-gate on state). (f) Isolation (quadruple-gate off state).

Table 1. Intrinsic elements of the GaAs HEMT switch with a gate size of 5 × 125 µm.

Table 2. Intrinsic parameters of GaAs HEMT switches with different gates.

Table 3. The error percentage of GaAs HEMT switches with different gates.