Rf isolator ferrite core8/17/2023 The circular conditions mentioned above are universal for all nonreciprocal junctions, and the circular performance parameters are ideal parameters to satisfy the circular conditions. Here YQ denotes the normalized admittance eigenvalue and sq denotes the normalized scattering matrix eigenvalue, so that the scattering parameters of non-reciprocal junctions can be expressed by their eigenvalues. When they satisfy the circumferential conditions, there must be: The normalized admittance eigenvalues can be used for discussion. If the distribution of the normalized values on the impedance circle and the phase angle difference between the corresponding S eigenvalues are 120o each other, the nonreciprocal junction is circular. If the non-reciprocal junction is lossless, the in-phase and in-phase excitation impedance eigenvalues of the double Y junction are derived by using the wave equation of the circular junction with positive and negative eigen-excitation. It is expressed by scattering matrix as follows: ![]() A matched lossless symmetrical three-terminal junction is proved to be a circulator by network theory analysis. The central conductor can be disc, Y-shaped, double Y-shaped or triangular shapes. The core of circulator is a non-reciprocal ferrite junction with external constant magnetic field. The radius of the metal conductor disk is R, the length of the small Y arm is R0, the coupling angle is_s wide, the electric length is_s, the width of the large Y arm is W, the coupling angle is_, the thickness of ferrite is H, and the thickness of the metal conductor is t. 1 is a schematic diagram of double Y-band junction circulator. At the same time, by combining the field theory with the circuit theory of the junction circulator, this paper deduces some general design formulas, gives a concise design process, and gives the simulation results combined with computer-aided design, which has a certain guiding significance for general designers.įig. ![]() According to the design, the simulation results meet the requirements of isolation greater than 26 dB, insertion loss less than 0.3 dB, echo loss greater than 26 dB, voltage standing wave ratio less than 1.14, and external radius size of the central conductor about 5 mm in the working frequency band, which basically meet the requirements of almost all GSM base stations for circulators. The object of this paper is a banded ferrite circulator with double Y junction as the central conductor in the base station. At present, circular circulators generally use central resonant conductors with disc junction, Y-junction, double Y-junction and triangle junction. ![]() Its working principle is to use the resonance effect produced by the central structure when the relationship between the RF field and the external bias magnetic field is satisfied, so as to obtain the circular effect. The circulator has unidirectional transmission characteristics, the incident signal can pass smoothly, and the reflected signal can not pass because it is absorbed by the absorption resistance. Nowadays, the application of microwave circulator is rapidly expanding to the fields of civil communication, energy technology, industry, agriculture and medicine. Microwave circulator has become one of the indispensable key devices in information communication, electronic countermeasures, aerospace and other fields. Because it has a series of non-reciprocal properties, it can be used to construct a series of microwave non-reciprocal devices such as circulators. Ferrite is a special magnetic material with spin-magnetic properties in microwave frequency band.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |