Design High Gain PHEMT LNA for Wireless Application at 5.8 GHz

This research present a design of a higher gain (68.94dB) for PHEMT LNA using an inductive drain feedback technique for wireless application at 5.8GHz. The amplifier it is implemented using PHEMT FHX76LP transistor devices. The designed circuit is simulated with Ansoft Designer SV. The LNA was designed using inductive drain feedback, inductive generation to the source, and the T-network as a matching technique was used at the input and output terminal. The low noise amplifier (LNA) provides a noise figure 0.64 dB and gain (S21) of 68.94 dB. The output reflection (S22), input reflection (s11) and return loss (s12) are -17.37 dB, -15.77 dB and -88.39 dB respectively. The measurement shows the stability were at 4.54 and 3-dB bandwidth of 1.72 GHz. The input sensitivity is -92 dBm exceeded the standards required by IEEE 802.16

RF Front End Receiver for WiMAX Application

This paper presents the design of a high gain, low noise direct conversion Radio frequency(RF) front-end receiver system. The Front end receiver is designed to operate at 5.8 GHz compliant with IEEE 802.16 WIiMAX standard. The system consists of a low noise amplifier (LNA), a radio frequency amplifier (RFA), a power divider and two band pass filters. The overall performance of the RF front-end receiver system produced a gain of 52.4 dB. A cascaded LNA designed for the system produced a high gain of 36.8 dB. The RFA contributed an extra gain 15.6dB. The overall noise figure achieved for the system is 3.7 dB. The return loss achieved is -25.5 dB for the RFA. The radio frequency bandwidth recorded for the system is above 1120 MHz. The measured power divider insertion loss is 2.80 dB. Using microstrip technology for designing the Chebyshev filter, the insertion loss is 3.00 dB and the channel bandwidth recorded is 107 MHz which can accommodate 4 sub channels IEEE WiMAX standard

Wideband 5.8 GHz Radio Frequency Amplifier with 3 dB Π- Network Attenuator Isolation

This paper presents a design of radio frequency amplifier (RFA), which operates at 5.8 GHz frequency for WiMAX application. The RFA designed used T-matching network consisting of lump reactive elements, 3 dB attenuator and microstrip line at the input and output impedance. The RFA developed in this project contribute a gain of 15.6 dB with overall noise figure of 2.4 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -12.4 dB, -25.5 dB and -12.3 dB respectively. The RFA used FET transistor EPA018A from Excelics Semiconductor Inc

Modeling of Indoor Wave Propagation Models from 1 G Hz to 10 G Hz

This paper presents the modeling of indoor wave propagation from 1 GHz to 10 GHz. Several obstacles such as partition, whiteboard, and door have been tested and measured their losses compare to line of sight. Horn antennas have been used as transmitter and receiver. An average attenuation between of this obstacle between 1.5 dB to 3.0 dB has been observed. Prediction model for this indoor propagation has been presented using suitable software. Finally, results, discussion, conclusions and further work are given

High Gain Cascaded Low Noise Amplifier Using T Matching Network

This project presents a design of high gain cascaded low noise amplifier (LNA), which operates at 5.8 GHz frequency for WiMAX application. The LNA designed used T matching network consist of lump reactive elements and microstrip at the input and output impedance. A cascaded LNA is developed in this project contributes a high gain of 36.8 dB with overall noise figure of 1.3 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -11.4dB, -39.1dB and -12.3dB respectively. The input sensitivity of the LNA is -80dBm which compliant with the IEEE 802.16 WiMAX application. The LNA used FET transistor FX 76 LP from Eudina In

5.8 GHz Radio Frequency Amplifier with 3 dB Π Network Attenuator

This paper presents a design of radio frequency amplifier (RFA), which operates at 5.8 GHz frequency for WiMAX application. The RFA designed used T matching network consist of lump reactive elements, 3 dB attenuator and microstrip line at the input and output impedance. The RFA developed in this project contributes a gain of 15.6 dB with overall noise figure of 2.4 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -12.4 dB, -25.5 dB and -12.3 dB respectively. The RFA used FET transistor EPA018A from Excelics Semiconductor Inc

High Gain Cascaded Low Noise Amplifier using T-Matching Network

This project presents a design of high gain cascaded low noise amplifier (LNA), which operates at 5.8 GHz frequency for WiMAX application. The LNA designed used T-matching network consisting of lump reactive elements and microstrip at the input and the output matching load uses quarter wavelength techniques. A cascaded LNA is developed in this project contribute a high gain of 36.8 dB with overall noise figure of 1.3 dB. The overall measured bandwidth measures is 1.240 GHz with S parameters S11, S12 and S22 measured are -11.4dB, -39.1dB and -12.3dB respectively. The input sensitivity of the LNA is -80dBm which compliant with the IEEE 802.16 WiMAX application. The LNA used FET transistor FHX 76 LP from Eudina Inc

Low Noise, High Gain RF Front End Receiver at 5.8GHz for WiMAX Application

This paper presents the design of a high gain, low noise direct conversion Radio frequency(RF) front-end receiver system. The Front end receiver is designed to operate at 5.8 GHz in compliant with IEEE 802.16 WiMAX standard. The system consists of a low noise amplifier (LNA), a radio frequency amplifier (RFA), a power divider and two band pass filters. The design process involved the use of software such as ADS 2000A, Ansoft Designer and MathCad. FET FHX76 LP is used in the design of the LNA due to its low noise figure and high impedance input. As for the RFA design,FET EPA018A was used. The LNA and the RFA used T lumped reactive element network and microstrip line matching network. Two 3 dBπ -attenuators were inserted at the input and output of the RFA to isolate the system from the reflected load power. A Wilkinson power divider is developed for two equal power structures using impedance microstrip line technique. Microstrip technology was used for designing the Chebyshev filter. The result of each module for the front end is presented

Low Noise, High Gain RF Front End Receiver at 5.8GHz for WiMAX Application

This paper presents the design of a high gain, low noise direct conversion Radio frequency(RF) front-end receiver system. The Front end receiver is designed to operate at 5.8 GHz in compliant with IEEE 802.16 WIiMAX standard. The system consists of a low noise amplifier (LNA), a radio frequency amplifier (RFA), a power divider and two band pass filters. The design process involved the use of software such as ADS 2000A, Ansoft Designer and MathCad. FET FHX76 LP is used in the design of the LNA due to its low noise figure and high impedance input. As for the RFA design, FET EPA018A was used. The LNA and the RFA used T lumped reactive element network and microstrip line matching network. Two 3 dBπ -attenuators were inserted at the input and output of the RFA to isolate the system from the reflected load power. A Wilkinson power divider is developed for two equal power structures using impedance microstrip line technique. Microstrip technology was used for designing the Chebyshev filter. The result of each module for the front end is presented

Preventive Antibacterial Therapy in Acute Ischemic Stroke: A Randomized Controlled Trial

BACKGROUND: Pneumonia is a major risk factor of death after acute stroke. In a mouse model, preventive antibacterial therapy with moxifloxacin not only prevents the development of post-stroke infections, it also reduces mortality, and improves neurological outcome significantly. In this study we investigate whether this approach is effective in stroke patients. METHODS: Preventive ANtibacterial THERapy in acute Ischemic Stroke (PANTHERIS) is a randomized, double-blind, placebo-controlled trial in 80 patients with severe, non-lacunar, ischemic stroke (NIHSS>11) in the middle cerebral artery (MCA) territory. Patients received either intravenous moxifloxacin (400 mg daily) or placebo for 5 days starting within 36 hours after stroke onset. Primary endpoint was infection within 11 days. Secondary endpoints included neurological outcome, survival, development of stroke-induced immunodepression, and induction of bacterial resistance. FINDINGS: On intention-to treat analysis (79 patients), the infection rate at day 11 in the moxifloxacin treated group was 15.4% compared to 32.5% in the placebo treated group (p = 0.114). On per protocol analysis (n = 66), moxifloxacin significantly reduced infection rate from 41.9% to 17.1% (p = 0.032). Stroke associated infections were associated with a lower survival rate. In this study, neurological outcome and survival were not significantly influenced by treatment with moxifloxacin. Frequency of fluoroquinolone resistance in both treatment groups did not differ. On logistic regression analysis, treatment arm as well as the interaction between treatment arm and monocytic HLA-DR expression (a marker for immunodepression) at day 1 after stroke onset was independently and highly predictive for post-stroke infections. INTERPRETATION: PANTHERIS suggests that preventive administration of moxifloxacin is superior in reducing infections after severe non-lacunar ischemic stroke compared to placebo. In addition, the results emphasize the pivotal role of immunodepression in developing post-stroke infections. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN74386719