Impedance Transformers

Zhurbenko, Vitaliy; Krozer, Viktor; Rubaek, Tonny

doi:10.5772/9408

Cited by 4 publications

(4 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The behavior of the reflection coefficient for 2-section NN impedance transformer is very similar to the single section quarterwave transformer [2], and therefore, is not considered here. Total electrical length of 6-section NN impedance transformer.…”

Section: Properties Of Nn Impedance Transformersmentioning

confidence: 99%

“…Compared to the traditional transformers based on distributed components, NN impedance transformers exhibit a number of advantages: they are more compact than the standard transformers based on quarter-wave sections [1,2]; they are less sensitive to fabrication errors than the compact transformers based on coupled lines [3]; and finally, their fabrication process is often compatible with the fabrication process of the transmission lines employed in the system. For example, if one part of the system with the output impedance of 50 Ω should be connected to another part with the input impedance of 300 Ω, this can be achieved by NN impedance transformer containing the same types of transmission line sections having mentioned (300 Ω, and 50 Ω) characteristic impedances.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nonsynchronous Noncommensurate Impedance Transformers

Zhurbenko¹,

Kim²

2012

PIER B

Self Cite

View full text Add to dashboard Cite

Abstract-Nonsynchronous noncommensurate impedance transformers consist of a combination of two types of transmission lines: transmission lines with a characteristic impedance equal to the impedance of the source, and transmission lines with a characteristic impedance equal to the load. The practical advantage of such transformers is that they can be constructed using sections of transmission lines with a limited variety of characteristic impedances. These transformers also provide comparatively compact size in applications where a wide transformation ratio is required. This paper presents the data which allows to estimate the achievable total electrical length and in-band reflection coefficient for transformers consisting of up to twelve transmission line sections in the range of transformation ratios r = 1.5 to 10 and bandwidth ratios χ = 2 to 20. This data is obtained using wave transmission matrix approach and experimentally verified by synthesizing a 12-section nonsynchronous noncommensurate impedance transformer. The measured characteristics of the transformer are compared to the characteristics of a conventional tapered line transformer.

show abstract

Section: Properties Of Nn Impedance Transformersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nonsynchronous Noncommensurate Impedance Transformers

Zhurbenko¹,

Kim²

2012

PIER B

Self Cite

View full text Add to dashboard Cite

show abstract

“…The last decade had shown significant increase involving microwave based system as reported in [6][7][8][9][10]. Microwave imaging is a technology which has potential application in diagnostic medical field.…”

Section: Introductionmentioning

confidence: 99%

Chebyshev Filter Applied to an Inversion Technique for Breast Tumour Detection

Elizabeth¹

2015

IJRET

View full text Add to dashboard Cite

Microwave imaging has been extensively studied in the past several years as a new technique for early stage breast cancer detection. The rationale of microwave imaging for breast tumour detection is significant contrast in the dielectric properties of normal tissue and malignant tumours. However, in practice noise present from the environments during screening/examination degrades the quality of the image. Inaccurate reconstructed image caused false/misleading interpretation of the image which leads to inappropriate diagnose or treatment to the patient. In the simulation works, noise is added to imitate the actual environment scenario. The two-dimensional (2D) object that identical to breast model is developed using numerical simulation to imitate the breast model. A filter is integrated with an iterative inversion technique for breast tumour detection to eliminate the noise. To assess the effectiveness of this approach, we consider the reconstruction of the electrical parameter profiles of 2D objects from measurements of the transient total electromagnetic field data contaminated with noise. Additive white Gaussian noise is utilized to mimic the effect of random processes that occur in the nature. This paper presents the filter settings and characteristics that affect the reconstruction of the image in order to obtain the most reliable and closer to the actual image. Selection of filter settings or design is important in order to achieve desired signal, most accurate image and provide reliable information of the object. Chebyshev low pass filter is applied in the Forward-Backward Time-Stepping (FBTS) algorithm to filter the noisy data and to improve the quality of reconstructed image.

show abstract

“…However, these techniques require new antenna designs to cover the LTE 17/13 and GSM 850/900 bands simultaneously. For impedance matching, L-, T-and pshaped impedance matching networks [10,11] and transformers [12] have been used. However, impedance transformers are usually used at low frequency bands below 500 MHz, such as the FM, HF, and UHF bands, and the matching network hardly achieves impedance matching over the 200 MHz bandwidth below 900 MHz.…”

Section: Introductionmentioning

confidence: 99%

Design of a coupled line feed structure for the wideband characteristic of a mobile internal antenna

Kim²,

Seong³

et al. 2013

Micro & Optical Tech Letters

View full text Add to dashboard Cite

A method to design an adjustable wideband impedance matching structure based on the impedance transformer concept is proposed in order to enhance wideband impedance matching. The designed coupled line feed structure (CLFS) provides a wide impedance characteristic via an operating principle similar to that of an impedance transformer. The CLFS enables tuning capability for the impedance characteristic of an inverted-F antenna (IFA) through adjustments in the line width and gap between the two CLFS spirals. By adding the proposed CLFS to the antenna feed, the bandwidth of the original IFA can provide about 22% wider coverage when compared with an IFA alone, especially over the LTE band, without changing the original antenna design. For frequencies below 1100 MHz, the impedance bandwidth of an IFA is about 40% at a center frequency of 862 MHz.

show abstract

Impedance Transformers

Cited by 4 publications

References 4 publications

Nonsynchronous Noncommensurate Impedance Transformers

Nonsynchronous Noncommensurate Impedance Transformers

Chebyshev Filter Applied to an Inversion Technique for Breast Tumour Detection

Design of a coupled line feed structure for the wideband characteristic of a mobile internal antenna

Contact Info

Product

Resources

About