A 4.5-5.8 GHz Differential LC VCO using 0.35 m SiGe BiCMOS Technology

In this paper, design and realization of a 4.5-5.8 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is implemented with 0.35´m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). A linear, 1300 MHz tuning range is measured with accumulation-mode varactors. Fundamental frequency output power changes between -1.6 dBm and 0.9 dBm, depending on the tuning voltage. The circuit draws 17 mA from 3.3 V supply, including buffer circuits leading to a total power dissipation of 56 mW. Post-layout phase noise is simulated -110.7 dBc/Hz at 1MHz offset from 5.8 GHz carrier frequency and -113.4 dBc/Hz from 4.5 GHz carrier frequency. Phase noise measurements will be updated in the final manuscript. The circuit occupies an area of 0.6 mm2 on Si substrate including RF and DC pads

Design of a 4.2-5.4 GHz Differential LC VCO using 0.35 m SiGe BiCMOS Technology

In this paper, a 4.2-5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35´m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). Phase noise is -110.7 dBc/Hz at 1MHz offset from 5.4 GHz carrier frequency and -113.5 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained utilizing accumulation-mode varactors. Phase noise is relatively low due to taking the advantage of differential tuning concept. Output power of the fundamental frequency changes between 4.8 dBm and 5.5 dBm depending on the tuning voltage. The circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit occupies an area of 0.6 mm2 on Si substrate including RF and DC pads

IEEE 802.11a uygulamaları için 4.2-5.4 GHz LC gerilim kontrollü Osilatör tasarımı (Design of a 4.2-5.4 GHz LC VCO for IEEE 802.11a applications)

In this paper, a 4.2-5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11 a standard is presented. The circuit is designed with AMS 0.35´m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). Phase noise is -110.7 dBc/Hz at 1MHz offset from 5.4 GHz carrier frequency and -113.5 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained utilizing accumulation-mode MOS varactors. Phase noise is relatively low due to taking the advantage of differential tuning concept. Output power of the fundamental frequency changes between 3mW and 3.5mW depending on the tuning voltage. The circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit occupyies an area of 0.6 mm2 on Si substrate

Design of a 4.2-5.4 GHz differential LC VCO using 0.35 mu m SiGeBiCMOS technology for IEEE 802.11a applications

In this paper, a 4.2-5.4 GHz, -Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35 mu m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). According to post-layout simulation results, phase noise is -110.7 dBc/Hz at 1 MHz offset from 5.4 GHz carrier frequency and -113.4 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained from the simulations, utilizing accumulation-mode varactors. Phase noise was also found to be relatively low because of taking advantage of differential tuning concept. Output power of the fundamental frequency changes between 4.8 dBm and 5.5 dBm depending on the tuning voltage. Based on the simulation results, the circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit layout occupies an area of 0.6 mm(2) on Si substrate, including DC and RF pads

Diamond semiconductor technology for RF device applications

This paper presents a comprehensive review of diamond electronics from the RF perspective. Our aim was to find and present the potential, limitations and current status of diamond semiconductor devices as well as to investigate its suitability for RF device applications. While doing this, we briefly analysed the physics and chemistry of CVD diamond process for a better understanding of the reasons for the technological challenges of diamond material. This leads to Figure of Merit definitions which forms the basis for a technology choice in an RF device/system (such as transceiver or receiver) structure. Based on our literature survey, we concluded that, despite the technological challenges and few mentioned examples, diamond can seriously be considered as a base material for RF electronics, especially RF power circuits, where the important parameters are high speed, high power density, efficient thermal management and low signal loss in high power/frequencies. Simulation and experimental results are highly regarded for the surface acoustic wave (SAW) and field emission (FE) devices which already occupies space in the RF market and are likely to replace their conventional counterparts. Field effect transistors (FETs) are the most promising active devices and extremely high power densities are extracted (up to 30 W/mm). By the surface channel FET approach 81 GHz operation is developed. Bipolar devices are also promising if the deep doping problem can be solved for operation at room temperature. Pressure, thermal, chemical and acceleration sensors have already been demonstrated using micromachining/MEMS approach, but need more experimental results to better exploit thermal, physical/chemical and electronic properties of diamond

Preclinical testing of a targeted TRAIL therapeutic for bone sarcoma

PhD ThesisBackground: TNF-related apoptosis-inducing ligand (TRAIL) can induce cell death in cancer cells after binding to its TRAIL receptors [TRAILR, Death Receptor 4 (DR4) and Death Receptor 5 (DR5)] while sparing non-malignant cells. The application of TRAIL provides an approach that can potentially overcome drug resistance and toxicity associated with high doses of conventional therapies. It could be administered alone or in combination with conventional therapies and, therefore, may offer a promising new approach to bone sarcoma treatment. Enhancing the cytotoxic effect of TRAIL involves targeting a tumour associated antigen (TAA). Here, the aim was to characterise bone sarcoma cells for TRAILR expression and to assess the effectiveness, both in vitro and in vivo of a novel TRAIL construct, neural/glial antigen 2 (NG2) targeted TRAIL (ScFvNG2-Fc-scTRAIL). Methods: Bone sarcoma cell lines were characterised for TRAILR and NG2 expression on RNA and protein level. Together with non-malignant cell lines, they were exposed to the novel TRAIL therapeutic (ScFvNG2-Fc-scTRAIL) in vitro and then tested in vivo in a newly developed xenograft model of dedifferentiated chondrosarcoma. Results: Surface DR5 was expressed in all cell lines examined (very high: HT1080, MG63; moderate: SW153, U2OS, TC71). NG2 was also expressed (very high: SW1353, MG63; moderate: U2OS, HT1080). ScFvNG2-Fc-scTRAIL demonstrated enhanced cytotoxicity in DR5- and NG2-expressing cell lines (MG63>HT1080>U2OS), which increased with doxorubicin and was also found in vivo when engrafting a luciferase expressing HT1080 cell line in a dedifferentiated chondrosarcoma mouse model. Conclusion: I demonstrate that a novel targeted TRAIL therapeutic, ScFvNG2-FcscTRAIL, has a selective and significant cytotoxic effect on cell lines expressing both cell surface DR5 and NG2, and these cytotoxic effects can be enhanced further with doxorubicin. Such combinations could minimise the risk of treatment failure due to drug resistance, a common problem of single agent approaches. Furthermore, these findings provide a framework for the clinical development of ScFvNG2-Fc-scTRAIL and could potentially be used in the neoadjuvant setting, which would be a shift from the usual convention of prioritising excision of the sarcoma

Kamu harcamalarının enflasyonist etkileri ve Türkiye’deki durumu

Bu araştırmada, 1980 döneminden günümüze kamu harcamalarının ve enflasyonun gelişimi ve kamu harcamalarının enflasyonist etkileri incelenmiştir. Devletin kamusal mal ve hizmet üretmek için yaptığı harcamalar olan kamu harcamaları, dar anlamda merkezi devlet örgütü ve yerel yönetimlerin harcamaları, geniş anlamda bunların yanısıra Kamu İktisadi Kuruluşlarının Sosyal Güvenlik Kuruluşlarının harcamaları ile vergi muafiyet ve istisnalarını kapsamaktadır. Kamu harcamalarının gelişimi izlendiğinde kamu harcamalarının ekonomik sınıflandırılmasının reel harcamalar transfer harcaması şeklinde olduğu görülmektedir. 1980 sonrası izlenen ekonomik politikanın asıl hedeflerinden biri, kamu kesiminin ekonomideki payının azaltılmasıdır. Nitekim GSMH, kamu harcamalarından daha fazla artmıştır. Kamu harcamaları reel olarak artmasına rağmen, GSMH içindeki payında azalma olmuş ancak 1990 yılından itibaren tekrar yükselerek %25'lere yaklaştığı görülmüştür. GSMH'nın %30'unu aşan 1998 yılı bütçe harcamaları, şu ana kadar GSMH içindeki özel kesim payının küçülmediği yani, devleti küçültmenin başarılamadığını göstermektedir. Devletin sosyal ve ekonomik görevlerinin artması gerçeği karşısında kamu harcamalarının zaman zaman dalgalanmalar göstermekle birlikte artış göstermesi kaçınılmaz bir sonuçtur. Kamu harcamalarının toplam olarak astronomik denilebilecek düzeylere gelmiş olması, maliye politikasının araç olarak etkinliğini arttırmıştır. Özellikle bu etkilerin ekonomik dengeyi sağlayıcı ya da bozucu yönde olabilmesi, sorunun önemini her geçen gün arttırmaktadır. Kamu harcamalarındaki bu artış, bir yandan milli geliri yükseltici yönde, bir yandan da genel ekonomi üzerinde genişletici ya da daraltıcı yönde önemli rol oynayabilmektedir. Günümüz ekonomilerinin en "önemli sorunu olan ve genel olarak FGD'de hızlı ve sürekli artışı belirtmek üzere kullanılan enflasyon talep-maliyet ve fiyat enflasyonu şeklinde bir sınıflandırmaya tabi tutulmaktadır. Özellikle Türkiye'de talep ve maliyet enflasyonu doğuran kaynakların başında kamu harcamalarının gittikçe hızlanan bir artış trendi göstermesi, rasyonellikten uzak destekleme alımları, KİT'lerin her yıl artan açıkları ve bunların Merkez Bankası kaynaklarından finanse edilmesi sayılabilir. Türkiye'de son yıllarda yaşanan yüksek oranlı enflasyonda hem toplam harcama artışı, hem de maliyet artışları etkili olmuştur. Konuyu kamu harcamalarının artışı olarak ele alırsak; artan kamu harcamalarına karşı özel tasarruflar, vergiler ve dış tasarruflar yeterince artırılamamıştır. Mal ve hizmet alımına yönelik kamu harcamalarının değeri enflasyon oranına paralel olarak artacağı gibi sosyal güvenlik harcamaları ve kamu sektörü ücret ödemelerinin enflasyonla birlikte artması da toplam kamu harcamalarını artırır. Maliye Bakanı Z. Temizel'e gören enflasyonla tam anlamıyla mücadele edilebilmesi için kamu harcamalarını disipline alacak bir harcama reformuna ihtiyaç duyulmaktadır. Kamuya ait tüm harcamaların bütçe ödenekleri içerisinde yapılması gerekmekte ancak kamu kurumlarının bütçeden yapamadıkları harcamaları vakıf, döner sermaye veya fon aracılığıyla gerçekleştirmeleri nedeniyle bunun enflasyonla mücadele programını olumsuz etkilediği görülmektedir. Sorgulanması gereken en önemli ve öncelikli husus harcamalar olmalıdır. 1997 Ocak-Kasım döneminde harcamalar %86,4 artış göstermiş ve 6.2 katrilyon TL. olmuştur. Devletin sosyal ve ekonomik görevlerinin artması gerçeği karşısında kamu harcamalarının zaman zaman dalgalanmalar göstermekle birlikte artış göstermesi kaçınılmaz bir sonuçtur. Ancak acil bir harcama reformu yapılması ve bütçe dışı hiçbir harcamaya izin verilmemesi suretiyle kamu harcamalarının enflasyonist etkisini kontrol altında tutmak mümkün görülmektedir

Design of a 4.2-5.4 GHz Differential LC VCO Using 0.35m SiGe BiCMOS Technology for IEEE 802.11a Applications

In this paper, a 4.2-5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). According to post-layout simulation results, phase noise is -110.7 dBc/Hz at 1MHz offset from 5.4 GHz carrier frequency and -113.4 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained from the simulations, utilizing accumulation-mode varactors. Phase noise was also found to be relatively low due to taking the advantage of differential tuning concept. Output power of the fundamental frequency changes between 4.8 dBm and 5.5 dBm depending on the tuning voltage. Based on the simulation results, the circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit layout occupies an area of 0.6 mm2 on Si substrate, including DC and RF pads