High linearity MMIC amplifiers for on-board satellite S-DMB converters

This paper presents the design, simulation and measurement of two GaAs P-HEMT high linearity amplifiers for S-DMB applications, operating in the S and UHF bands. The amplifiers are part of a high linearity downconverter, so a specific topology and an active matching network have been chosen to achieve a high OIP3 value as well as good input and output return losses without using any external components. The S-band and UHF-band amplifiers exhibit an OIP3 of 23 dBm and 27 dBm respectively. They have also been measured included in a down-converter, achieving a total gain of 19 dB, an ouput P1dB of 10.5 dBm and a OIP3 of 31 dBm.This work has been carried out with the support of the project AMURA, TEC2009-14219-C03-03 of the Ministerio de Ciencia e Innovación of the Spanish Government, and with the project “Acuerdo específico de colaboración para el soporte y consultoría en el area de TTC & RF activa” with Thales Alenia Space, Spai

Load-pull circles analysis method for aplying the outphasing technique in power amplifier design

This paper presents a simple way of analyzing the suitability of a power amplifier for its use in an outphasing system. Simple steps are presented, allowing the designer to decide in advance if the outphasing technique will improve the efficiency versus back-off characteristic of the amplifier. For validating the method, an outphasing system for a Class AB amplifier has been designed, simulated and measured. In addition, a Class D amplifier has been also simulated to make a comparison of the results

Diseño RF de un transmisor MIMO UWB

An ultra wide band MIMO transmitter using a six way splitter is presented in this document. It has been designed as an hybrid circuit in an Arlon substrate to be confined in the smallest space at the desired frequency range. The aim of the proposed system is the integration of MIMO and UWB to obtain most advantages of both technologies and to balance their disadvantages. Although UWB is a suitable option if inexpensive costs are taking into account, it is limited to short range applications due to its very low transmitted power. But MIMO technique in UWB systems improve the link robustness of UWB or its data rate, exploiting multipath and diversity gain to improve the SNR without consuming extra radio frequency. This is only valid if the antennas are placed appropriately distance among them

LNA de bajo coste para aplicaciones de banda Ultra-ancha

This paper presents the design, simulations and measurements of a fully integrated low noise amplifier (LNA) for Ultra-Wideband applications. The circuit has been implemented in a 0.4 μm silicon-germanium (SiGe:C) bipolar technology which features a 46 GHz cut-off frequency. The LNA exhibits in simulation a flat gain of 23 dB from 3 to 9 GHz and shows a noise figure lower than 5 dB over the whole band. The feedback Darlington configuration allow to obtain good return losses without any matching network. The output 1 dB compression point is below –5 dBm within the band of interest. The UWB input signal is correctly amplified by the LNA and the output spectrum meet the restrictive PART 15 mask of the FCC

Mejora en la eficiencia de un amplificador de potencia mediante técnicas de seguimiento de envolvente

This paper presents the `Envelope Following’ Technique for raising power efficiency in mobile communication systems. The designed power supply system includes a 2.13 GHz power amplifier in which the input battery voltage of 5 V is boosted to a variable voltage output of 28 V depending on the incoming radiofrequency envelope. This variable voltage is obtained using an envelope detector and a dc-dc boost converter. For an output power level of 45 dBm, the power efficiency increases from 72.4% to 85.4% extending battery life over 1.2 times

VCO de bajo ruido de fase en banda S completamente integrado para aplicaciones embarcadas

A low phase noise common base Colpitts voltage controlled oscillator for satellite communications is presented. The circuit is fully integrated and is fabricated using a space qualified commercial InGaP HBTtechnology. The circuit does not include any custom components since the reliability in space applications is very important and it can only be achieved through library modeled elements. The VCO operates from 3.3 to 3.59 GHz with a 4% tuning range, and with an output power of 0.5 dBm for a frequency of 3.5 GHz. It shows a very good phase noise characteristic, showing -115.5 dBc/Hzat 1 MHz offset in measurements. The overall dc power consumption of the VCO core is quite low, with a value of 32.5mW for a supply voltage of 5 V

LNA en tecnología de SiGe para aplicaciones WLAN IEEE802.11a/HiperLAN

A MMIC for the IEEE 802.11a/HiperLAN WLAN standard has been designed and fabricated in a 0.4-μm SiGe BiCMOS technology. The IC is part of a direct conversion receiver and is composed of three differential stages to ensure good output phase balance and high isolation. The LNA exhibits in simulation a gain of 14 dB and wideband input and output matching. An output 1-dB compression point of –6 dBm and a noise figure of 4.6 dB were achieved at the frequency of interest. The MMIC LNA was mounted and measured to test the similarity with simulations

VCO CMOS de bajo ruido a 10 GHz en tecnología SiGe de 0.4μm

A 10 GHz CMOS VCO design in 0.4μm SiGe technology is presented in this paper, providing a good compromise between power consumption, noise, tunning range and chip area. This design is intended to be used in a frequency synthesizer for the 5150-5250MHz band in a direct conversion system in which would run at double frequency to avoid adverse effects such as frequency pulling and LO leakage. The phase noise at 1-MHz frequency offset from the carrier is below -109dBc/Hz, with a maximum power consumption of 22.6mW. The tunning range under the presented load conditions is about 6.3%, and the VCO itself occupies an area of only 0.075mm2

Amplificador MMIC de alta linealidad en banda S para aplicaciones S-DMB embarcadas

This paper presents the design, simulation and measurement of an S-band GaAs P-HEMT high linearity amplifier. The amplifier is part of the down-converter in the on-board satellite repeaters of an S-DMB system that provides digital mobile broadcast/multicast services. The topology of the amplifier has been chosen to achieve a high linearity, and a wideband input matching network has been included in order to obtain the required specifications without using any external components. The S-band amplifier has been measured showing an OIP3 of 23 dBm and a gain of 15.3 dB, obtaining also good values of input and output matching. These results are obtained in the first fabrication run of the circuit

Estudio de la influencia de las librerías de RF en tecnología SiGe: aplicación en el diseño de LNA’s para WLAN

This paper presents the study of the influence of RF librraries on the design of MMICs (Monolithic Microwave Integrated Circuits). Two low noise amplifiers (LNA’s) for the WLAN 802.11a standard have been designed using different SiGe Technologies: 0.4 μm CDR1 BiCMOS from Freescale and 0.2 μm SGB25VD from IHP. The LNA’s have been simulated and measured in order to verify the importance of the component models that the library offers. The comparison of both libraries show that the IHP models are more reliable at higher frequencies that the Freescale ones. It has also been noted the lack of a transmission line model for high frequency designs in both technologies although in this case the influence of these lines in the performance of the circuits is not too significant