An x-band RFIC active phase shifter

Abstract— An active RFIC X-band phase shifter is implemented using IHP SiGe HBT 0.25 μm SGB25V technology with an improved vector sum method. The chip is formed by a three way Wilkinson power divider, three phase delays for 0-120-240 degrees, three similar RFIC LNAs and a final three way Wilkinson power combiner on the same chip and occupies an area of 4x1.8 mm2. The circuit provides both phase and amplitude control without the need of any additional digital circuitry. Phase shifting is simply based on the weighted vector sum of three vectors which are separated by 120º from each other. All 0-360 degree phase can be scanned simply by this method with the addition of amplitude control. The RFIC LNA circuit is fabricated and measurement results show that LNA has a gain of 10 - 13 dB with in the band of 6-9 GHz and 2-3 dB NF within the same band. The simulation results show that the phase can be scanned from 0-360 degrees with average 7 degree resolution for a 2 dB amplifier gain change. The gain of the overall active phase shifter circuit is 12-13 dB with output gain flatness is 1 dB and the circuit consumes 15.36 mW power. The circuit combines the amplifier with phase shifter and can be used for X-band applications

Printed dipole array fed with parallel strip line for Ku-band applications

This paper presents the design procedure of a printed dipole antenna and 1D array configurations of the single dipole element in the Ku-Band with its metallic reflector plane parallel to the array plane. The proposed antenna has a natural beam tilt which is useful for some specific applications. Several array configurations in 1D are simulated and tested. The effect of mutual coupling among each array elements is also investigated. Required modifications on the individual array element and the feed structures due to the effect of mutual coupling are examined. The single dipole and array of dipole has measured VSWR values smaller than 2 in the Ku-Band with simulated gains of 5.7 dBi and 12 dBi, respectively. All the simulations are performed with ADS-2006A software and measurements are performed in an anechoic chamber

A tunable X-band SiGe HBT single stage cascode LNA

This paper presents an X-band silicon-germanium (SiGe) single stage cascode tunable low-noise amplifier (LNA) for active phased array transmit/receive modules. LNA is implemented by using IHP SiGe heterojunction bipolar transistors (HBTs) 0.25-μm SGB25V technology. Cadence is used in collaboration with ADS during schematic and layout design and the results depict that designed LNA dissipates 15.36 mW from an 2.4 V DC power supply and the maximum gain around 18 dB in X-band while not exceeding the 2.4 dB noise figure (NF). Reverse gain of the LNA is very low (<-40 dB). Input terminal is matched so that S11 is below -10 dB in X-band

Bachian Gravity in Three Dimensions

In three dimensions, there exist modifications of Einstein's gravity akin to the topologically massive gravity that describe massive gravitons about maximally symmetric backgrounds. These theories are built on the three-dimensional version of the Bach tensor (a curl of the Cotton-York tensor) and its higher derivative generalizations; and they are on-shell consistent without a Lagrangian description based on the metric tensor alone. We give a generic construction of these models, find the spectra and compute the conserved quantities for the Banados-Teitelboim-Zanelli black hole.Comment: 17 pages, a note added on MM

Determining spatial distribution of communities in Ottoman districts in late 19th century by Gini inequality measurements

Osmanlı toplumunda günümüzden farklı olarak heterojen cemaat yapısı mevcuttur. Dinsel aidiyet temelinde yapılan milliyet tanımında, nüfus sayımlarında yedi büyük milliyet vardır. 19. yüzyılın sonunda yapılan nüfus sayımlarında 33 vilayetteki cemaatlerin sayısal dağılımları mevcuttur. Bu çalışmada yedi cemaatin her birinin, Osmanlı vilayetleri içerisindeki coğrafi “spatial” dağılımlarının karakteri incelenmiştir. Uygulama olarak Gini eşitsizlik ölçüsü seçilmiştir. Buradan hareketle Müslim, Rum ve Ermeni cemaatlerinin Osmanlı toplumunun demografik açıdan asli unsurları olduğunu savunmak mümkündür. Çalışmadaki diğer önemli bir sonuç ise, yabancıların mekânsal demografik dağılımlarındaki lokalizasyon çerçevesinde uluslar arası pazar ekonomisinin Osmanlı coğrafyasında 19. yüzyıl sonunda da bölgesel düzeyde kaldığı ve tüm ülke coğrafyasına henüz yayılamadığıdır.The Ottoman society had a heterogeneous community structure that is different from our time. There were seven big communities that were determined by the base religious identity in censuses. There were numerical distributions of the communities in the 33 provinces in the 19th century. In this study, the character of geographical spatial distributions of communities with Gini inequality measurement is examined. Findings show that, the Muslim, Rome and Armenian communities were the essential elements. The other result found by this study is that, at the end of the 19th century international market economy remained in regional level, not at the national level

A Study on Preferred Learning Styles of Turkish EFL Teacher Trainees

Since people have different ways of perception, levels of motivation, and attitudes towards teaching and learning they consistently differ from each other in their preferences of learning and acquiring knowledge. Therefore, the more instructors understand the differences, the better chance they have of understanding and meeting the diverse learning needs of their students. The present study has been conducted to investigate the Turkish ELT students’ learning style preferences in relation to gender and age to see if there is any relationship between achievement and learning style preferences. To perform the aim of the study Wintergerst and DeCapua’s (1999) learning style indicator (LSI) was administered on 249 English trainees. To find the male and female students’ learning style preference differences separately, t-test was utilized. The result indicated that Turkish students are mostly group-oriented learners and learn best through interacting with other students while learning. Gender also varies according to the three orientation areas under investigation. In the current study, no relation between achievement and learning style has been identified

Feminizmin Din Dili ve Söylemi

Feminizm modern zamanlarda Batı’da ortaya çıkmış bir akım olup kadın haklarını savunmak üzere kendisini tanımlamıştır. Bugüne gelinceye kadar feminizm kendi içinde çeşitlilik kazanarak dünya ölçeğine yayılmıştır. Bu makalede feminizm başından itibaren dine dair geliştirdiği dil ve söylemlerin analizi hadeflenmektedir. Genel olarak bakıldığında ise feminizmin dine yaklaşımında bir olumsuzluk görülmektedir. Makalede öncelikle genelde dinler özelde ise İslam’ın kadına dair söylemleri tasvir edilmektedir. Özellikle üç büyük dinin kutsal kitaplarında kadına dair dil ve söylem anahatlarıyla belirtilmektedir. Ardından tasnif edilen belirli konular etrafında feminizmin bu söylemleri nasıl değerlendirdiği örneklerle anlatılmaktadır. Feminizm bu konuda temel söylemi, dinlerin kadınları ikinci konumda gördükleri şeklindedir. Bu durum bugüne gelinceye kadar feminist düşüncede dinle hesaplaşma gibi bir dilin yaygınlaşmasını birlikte getirmiştir. Ancak feminizm Batı dışında farklı coğrafyalara yayılması oranında dinle daha farklı ilişkiler geliştirdiği gözlemlenmektedir

“TANRI” KAVRAMI VE TOPLUMSAL İZDÜŞÜMÜ

Din olgusunun kutsal kavramı dışında ilintilendirildiği ve din etrafındaki tartışmaların odaklandığı “Tanrı” kavramı, tarihsel süreç içerisinde sosyal değişmelere de paralel olarak özel ve ayrıcalıklı bir konu olmuştur. Her ne kadar din olgusuna çok farklı açılardan tanımlar bulunsa da, Tanrı kavramına yaklaşımlar daha üst bir dile denk gelmektedir. Esasen Turan Koç’un da belirttiği gibi, “öteki tanım ve yaklaşımların önemi kabul edilmekle birlikte, daha çok dar anlamda din dilinin Tanrı hakkında konuşmak olduğu söylenebilir. Koç, 1995: 11 Fakat Tanrı hakkında konuşmak her ne kadar dar bir alan gibi görülse de, aslında dünya, evren, insan hakkındaki her konuşmanın Tanrı kavramını da konuşmayı icbar edeceği gözönüne alınırsa, ne denli geniş ve aynı zamanda gizemliliği ölçüsünde tanımı zor bir alana tekabül edeceği kabul edilmelidir

A comprehensive analysis of postpartum depression and delivery characteristics: a cross-sectional study

Objective: We attempted to identify risk factors for postpartum depression (PPD) by evaluating individuals in terms of their birth patterns, as well as other characteristics, including income level, smoking habits, number of children, age, and history of antidepressants. Methods and results: Participants completed a questionnaire consisting of three sections: demographic characteristics, delivery characteristics, and Edinburgh Postpartum Depression Scale. Participants with a depression medical history had a higher depression level during the postpartum. There were significant correlations between postpartum depression, the husband’s working status, the desire fo r the pregnancy, and the patient’s depression medical history. PPD levels did not differ for other birth-related variables. Conclusions: It is important to use appropriate screening tools to identify mothers with PPD in the community. It is also important to instruct mothers about how to care for both their babies and themselves. For this reason, the mother should be monitored for the first six months postpartum, and social - familial support should also be monitored

Detection and partial characterization of two distinct walnut isolates of cherry leaf roll virus (CLRV)

Two new cherry leaf roll virus (CLRV) isolates (Ah and Ad) were isolated and detected from traditionally-grown walnuts that showed severe apical necrosis and chlorotic spots in systemically infected Cheneopodium amaranticolor, in the eastern part of Turkey. The 404 and 405 bp long DNA fragments of the 3’-non-coding region of both isolates from PCR reactions were cloned and sequenced. A significant genetic variability (up to 14% divergence between sequences) was found within the 3’ terminal region of viral genome of CLRV Turkish isolates compared with the isolates in databases. The sequence of Ad isolate was found to share 84 to 98% and the Ah isolate was found to share 85 to 97% nucleotide identity with corresponding sequences of the selected world isolates. An RNA riboprobe generated for CLRV-Ad isolate reacted also with the CLRV-Ah isolate in dot blot molecular hybridization test. Positive reactions were still visible in hybridization test when the extracts of infected fresh and dried leaf tissues of C. amaranticolor diluted 1:20. Western blot analysis revealed that the molecular mass of the coat protein of about 52 kDa for both isolates.Keywords: Walnut, CLRV, 3’ non coding regio