A planner Doherty power amplifier with harmonic suppression with open and short ended stubs

This paper presents a new Doherty power amplifier (DPA) with harmonics suppression. A Wilkinson power divider (WPD) with open-ended and short-ended stubs is designed to suppress unwanted signals. To design the power divider in the circuit of the DPA, even and odd mode analyses are utilized. The proposed design operates at range of 1.2–1.6 GHz. The linearity of the suggested DPA is increased about 6 dBm, in comparison with the main amplifier. The designed Doherty amplifier has a power added efficiency (PAE), drain efficiency (DE) and Gain about 60, 61% and 19 dB, respectively. The designed WPD suppresses 2nd up to 14th harmonics with more than 20 dB suppression level, which is useful for suppressing unwanted harmonics in DPA design. ATF-34143 transistors (pHEMT technology) are used for this DPA amplifier design. The main amplifier has class-F topology and class-F inverse topology is used for auxiliary amplifier.

Some results in types of extensions of MV-algebras

We introduce the notions of zero divisor and extension, contraction of ideals in MV-algebras and several interesting types of extensions of MV-algebras. In particular, we show what kinds of extensions MV-algebras will lead in a homeomorphism of the spectral topology and inverse topology on minimal prime ideals. Finally, we investigate the relations among types of extensions of MV-algebras.

On a complete topological inverse polycyclic monoid

We give sufficient conditions when a topological inverse $\lambda$-polycyclic monoid $P_{\lambda}$ is absolutely $H$-closed in the class of topological inverse semigroups. For every infinite cardinal $\lambda$ we construct the coarsest semigroup inverse topology $\tau_{mi}$ on $P_\lambda$ and give an example of a topological inverse monoid $S$ which contains the polycyclic monoid $P_2$ as a dense discrete subsemigroup.

On inverse topology problem for Laplace operators on graphs

Laplacian operators on finite compact metric graphs are considered under the assumption that matching conditions at graph vertices are of $\delta$ type. Under one additional assumption, the inverse topology problem is treated. Using the apparatus of boundary triples, we generalize and extend existing results on necessary conditions of isospectrality of two Laplacians defined on different graphs. A result is also given covering the case of Schrodinger operators.

TWO SPACES OF MINIMAL PRIMES

This paper studies algebraic frames L and the set Min (L) of minimal prime elements of L. We will endow the set Min (L) with two well-known topologies, known as the Hull-kernel (or Zariski) topology and the inverse topology, and discuss several properties of these two spaces. It will be shown that Min (L) endowed with the Hull-kernel topology is a zero-dimensional, Hausdorff space; whereas, Min (L) endowed with the inverse topology is a T1, compact space. The main goal will be to find conditions on L for the spaces Min (L) and Min (L)-1 to have various topological properties; for example, compact, locally compact, Hausdorff, zero-dimensional, and extremally disconnected. We will also discuss when the two topological spaces are Boolean and Stone spaces.