# A 2.4-GHz Fully-Integrated GaAs pHEMT Front-End Receiver for WLAN and Bluetooth Applications
## 3 Measurement Results  
Figure 5 reveals a chip photograph of the proposed front-end receiver on a printed circuit board (PCB), which was provided by a foundry named Huanzhou Lion in mainland China with both 0.25 \(\upmu\)m E-mode and 0.5 \(\upmu\)m D-mode pHEMTs. All measured results are obtained taking into account the effect of the full evaluation board and the block diagrams of measurement setup are shown in Figure 6.  
The S-parameters of the proposed receiver were measured using Keysight E5071C ENA vector network analyzer, as depicted in Figures 7-10. In this study, the circuit simulations were performed using Keysight's Advanced Design System software with a GaAs pHEMT design kit. The effect of the bond wire has been taken account in simulation. In high gain mode, the LNA achieves power gain of 20 dB at 2.4 GHz drawing 11 mA of current from 5 V power supply as shown in Figure 7. The lower and upper 3-dB bandwidth points are 2.2 and 3 GHz, respectively. In bypass mode, the LNA has an  
Figure 5: Chip photograph of proposed front-end receiver on an evaluation board.  
Figure 6: Block diagrams of measurement setup of (**a**) S-parameters, (**b**) noise figure (NF) and (**c**) large signal performance.  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Mode** & \(\mathbf{M_{sw1}}\) & \(\mathbf{M_{sw2}}\) & \(\mathbf{M_{sw3}}\) & \(\mathbf{M_{sw3}}\) \\ \hline High gain mode & off & on & off & off \\ Bypass mode & on & off & on & on \\ \hline \hline \end{tabular}
\end{table}
Table 3: Operating state of four switches in receiving path.  
Figure 8. The measured IL is 0.6 dB at 2.4 GHz in transmit switch mode while 0.8 dB in Bluetooth switch mode as shown in Figures 9 and 10, and the switches can handle more than 33 dBm of input power. It is obvious that all measured input and output return losses had exceeded 10 dB at 2.4 GHz with fully on-chip impedance matching networks.  
Figure 7. Measured and simulated small-signal S-parameters of proposed front-end receiver in high gain mode.  
The NF and large signal parameters for linearity were measured using an Agilent N9030A PXA signal analyzer with Agilent 346B noise source and Agilent E4438C ESG vector signal generator. Figure 11 exhibits that the measured NF is below 1.7 dB in high gain mode for 2.4-2.5 GHz. Power handling capability of the LNA is critical for WLAN applications in order to avoid LNA compression and preserve the modulated signal received at the front-end. Figure 12 illustrates that the IIP3 of the LNA in high gain mode is 6 dBm with the condition that the two-tone frequencies are 2.37 GHz and 2.43 GHz, respectively.  
Figure 10: Measured and simulated small-signal S-parameters of proposed front-end receiver in Bluetooth switch mode.  
Figure 9: Measured and simulated small-signal S-parameters of proposed front-end receiver in transmit switch mode.  
Figure 11: Measured and simulated NF of proposed front-end receiver in high gain mode.  
Figure 12: Measured and simulated input third-order intercept point (IIP3) of proposed front-end receiver in high gain mode.  
last row represents the comprehensive performance of the references. Here, the FOM is expressed as follows:  
\[FOM=\frac{G\cdot IIP3(mW)}{P_{DC(mW)}\cdot(NF_{\min}-1)} \tag{10}\]  
where \(G\) represents the voltage gain of the referred LNA in magnitude, and (\(NF_{min}\)-1) represents the excess noise factor in magnitude. Comparing the performance in terms of power gain, \(NF\) and cost, the measured power consumption of the proposed front-end encoder is slightly large due to the additional logic controller for mode switching. The proposed design presents excellent performance according to the calculation of \(FOM\). With fully on-chip input and output matching networks, as well as bias and logical circuitry, this receiver can demand the wireless 802.11 b/g standards.