UM10380 User manual for the BGU7005 GPS LNA evaluation board Rev.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB Revision history Rev Date Description 01 3 November 2009 First Release. Contact information For additional information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com UM10380_1 User manual © NXP B.V. 2009. All rights reserved. Rev.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 1. Introduction NXP Semiconductors’ BGU7005 is a low-noise amplifier for GPS receiver applications in a plastic, leadless 6 pin, extremely thin small outline SOT886 package. It has a gain of 16.5 dB gain and a noise figure of 0.8 dB, It has superior linearity performance to suppress interference and noise from co-habitation cellular transmitters while retaining sensitivity.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 2. General description NXP Semiconductors’ BGU7005 GPS low noise amplifier is dedicated for the GPS frequency band. The integrated biasing circuit is temperature stabilized, which maintains a constant current over temperature. It also enables the superior linearity performance of the BGU7005. It is also supplied with an enable function that allows it to be controlled with a logic signal. In disabled mode it only consumes less that 1µA.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 3.1 Application Circuit The circuit diagram of the evaluation board is shown in Fig 2. With jumper JU1 the enable pin can be controlled to either to Vcc or GND. X3 GND Ven Vcc X4 JU1 C1 5 RF in X1 L1 4 3 BGU7005 RF out 6 X2 1 2 Fig 2. Circuit diagram of the BGU7005 evaluation board 3.2 Board Layout Fig 3. Printed circuit board lay-out of the BGU7005 GPS LNA evaluation board UM10380_1 User manual © NXP B.V. 2009. All rights reserved. Rev.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 3.3 PCB layout A good PCB layout is an essential part of an RF circuit design. The evaluation board of the BGU7005 can serve as a guideline for laying out a board using the BGU7005. Use controlled impedance lines for all high frequency inputs and outputs. Bypass Vcc with decoupling capacitors, preferably located as close as possible to the device.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 4. Required Equipment In order to measure the evaluation board the following is necessary: DC Power Supply up to 30 mA at 1.5 V to 2.85 V; Two RF signal generators capable of generating an RF signal at the operating frequency of 1575.42 MHz, as well as the jammer frequencies 850 MHz, 1713.42 MHz, 1850 MHz and 1851.42 MHz; An RF spectrum analyzer that covers at least the operating frequency of 1575.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 9. For noise under jamming conditions, the following is needed. A 15dB ENR noise source, a directional coupler, GPS band pass filter, a noise-figure analyzer or a spectrum analyzer with noise option can be used. See Fig 12 Fig 5. BGU7005 evaluation board including its connections 6.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB Fig 6. O-IIP3 at Vcc = 1.5 V Fig 7. O-IIP3 at Vcc = 1.8 V Fig 8. O-IIP3 at Vcc = 2.85 V 6.2 In-band 1dB gain compression due to 850 MHz and 1850 MHz jammers As already stated before, signal levels in the GPS frequency band of –130 dBm average will not cause linearity problems in the GPS band itself. This of course is also valid for the 1 dB gain compression in-band. The 1 dB compression point at 1575.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB Four port NWA. 3 1 4 2 CAB1 CAB3 CAB2 X3 BGU7005 GPS LNA EVB GND Ven Vcc X4 JU1 C1 5 -20dB RF in Directional coupler L1 4 3 6 BGU7005 1 X1 RF out X2 2 Fig 9. Setup for 1 dB compression with jammers The gain was measured in the GPS frequency band between port 1 and 2, while simultaneously a jammer power signal was swept on port 3.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 7. Noise figure as function of jammer power at 850 MHz and 1850 MHz Noise figure under jamming conditions is a measure of how the LNA behaves when e.g. a GSM TX interfering signal is at the input of the GPS antenna. To measure this behavior the setup shown in Fig 12 is used. The jammer signal is coupled via a directional coupler to the DUT: this is to avoid the jammer signal damaging the noise source.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 8. Typical evaluation board results Table 2, typical results measured on the Evaluation Boards. Operating Frequency is f=1575.42MHz unless otherwise specified; Temp = 25 °C. Parameter Symbol BGU7005 BGU7005 BGU7005 Unit Supply Voltage Vcc 1.5 1.8 2.85 V Supply Current Icc 4.6 4.7 5.2 mA Noise Figure NF 0.86 0.85 0.86 dB 8.4 10 8.91 16.3 16.4 16.8 14.6 14.2 15.2 [1] 850MHz Power Gain 1575.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 9. Legal information 9.1 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. 9.
UM10380 NXP Semiconductors BGU7005 GPS LNA EVB 10. Contents 1. 2. 3. 3.1 3.2 3.3 3.4 3.4.1 4. 5. 6. 6.1 6.2 7. 8. 9. 9.1 9.2 9.3 10. Introduction .........................................................3 General description.............................................4 Application Board ...............................................4 Application Circuit..................................................5 Board Layout .........................................................5 PCB layout ................
