Philips Semiconductors B.V. Gerstweg 2, 6534 AE Nijmegen, The Netherlands Report nr. : RNR-T45-98-B-0709 Author : R. Damen Date : 1998-October-30 Department : Philips Semiconductors Product Group : Discrete SemiConductors - Nijmegen (Netherlands) Copy : APPLICATION NOTE DEMOBOARD FOR BGA2003 • Description of product BGA2003: RF transistor with internal bias circuit. Benefit is lower component count, internal compensation for temperature and diffusion spread. • Application Area Low noise amplifiers for CDMA, DECT, GSM, PCS with low component count. • Presented Application The application presents a low noise amplifier for CDMA at 1930-1990 MHz. Supply voltage is 3V and supply current 10 mA. Only output matching is needed. • Main results An amplifier has been designed and tested with >12.3 dB gain, IP3in=5 dBm, VSWRin,out<1:2, and <2 dB Noise Figure at 1930-1990 MHz. 3 Volt, 10 mA supply. 1/20/00 1 Philips Semiconductors B.V. Abstract Philips’ double poly fifth generation technology makes it possible to design high performance MMICs (Microwave Monolithic Integrated Circuits). The advantage of such MMICs is a higher functionality and a lower component count for high frequency applications. This application note describes a design made with the BGA2003. The BGA2003 is a high frequency transistor with integrated bias and control input. The application described here is specially intended as CDMA LNA (Low Noise Amplifier) for the 1930-1990 MHz frequency region. The design was intended to show the following performance: Gain > 12dB, NF < 2 dB, IP3in > +2 dBm, VSWRin,out < 1:2, Vsupply = 3V. The following appendices can be found next: -Circuit diagram and layout drawing -Component values -Measured results -Conclusions and recomendations 1/20/00 2 Philips Semiconductors B.V. Circuit diagram and Layout drawing: Vsupply Vcontrol C1 R2 in Lout R1 out Cout Cin BGA2003 Component Values Component R1 R2 C1 Cin Lout Cout uS1 MMIC PCB Value 22 2200 8.2pF 8.2pF 3.9nH 1.0pF BGA2003 - Type 0603 Philips 0603 Philips 0603 Philips 0603 Philips 0603 TDK MLG1608 0603 Philips PCB-stripline 50Ω, via Philips SOT343R2 FR4 Comment Supply decoupling Current setting RF-short to ground Input match, DC-decoupling Output match Output match see figure below ε R ~ 4.6, H = 0.5 mm Stripline and via dimensions 1/20/00 3 Philips Semiconductors B.V. Measured values: Vsupply = 3V, Vcontrol = 3V, Isupply = 9.4 mA, Icontrol = 0.84 mA VSWRin VSWRout S21 S12 IP3in NF @ 1930 MHz 1.85 1.53 12.6 dB -17.5 dB +5 @ 1990 MHz 1.81 1.85 12.2 dB -17.1 dB +5.3 2 dB 1.9 dB remark: Pin=-25 dBm, ∆f=1 MHz Conclusions and recomendations: From the measured results it can be found that the desired performance can be delivered. The IP3 is even a lot higher than required. Therefore one could try to lower the current in order to have a less power consuming application. Because the gain would go down and matching components on the input would be necessary to compensate for this, that approach was not used in this design. When evaluating the demoboard, one might find that the LNA is oscillating when both input and output are open, and when all DC voltages are applied. Under normal operating conditions (VSWRin,out< 1:7) there is however no problem. 1/20/00 4