Logarithmic circuit with wide dynamic range

A circuit deriving an output voltage that is proportional to the logarithm of a dc input voltage susceptible to wide variations in amplitude includes a constant current source which forward biases a diode so that the diode operates in the exponential portion of its voltage versus current characteristic, above its saturation current. The constant current source includes first and second, cascaded feedback, dc operational amplifiers connected in negative feedback circuit. An input terminal of the first amplifier is responsive to the input voltage. A circuit shunting the first amplifier output terminal includes a resistor in series with the diode. The voltage across the resistor is sensed at the input of the second dc operational feedback amplifier. The current flowing through the resistor is proportional to the input voltage over the wide range of variations in amplitude of the input voltage

The thin film microwave iris

Development of waveguide iris for microwave coupling applications using thin film techniques is discussed. Production process and installation of iris are described. Iris improves power transmission properties of waveguide window

Nanomechanical resonators operating as charge detectors in the nonlinear regime

We present measurements on nanomechanical resonators machined from Silicon-on-Insulator substrates. The resonators are designed as freely suspended Au/Si beams of lengths on the order of 1 - 4 um and a thickness of 200 nm. The beams are driven into nonlinear response by an applied modulation at radio frequencies and a magnetic field in plane. The strong hysteresis of the magnetomotive response allows sensitive charge detection by varying the electrostatic potential of a gate electrode.Comment: 8 pages, 6 figure

Radio frequency pulsed-gate charge spectroscopy on coupled quantum dots

Time-resolved electron dynamics in coupled quantum dots is directly observed by a pulsed-gate technique. While individual gate voltages are modulated with periodic pulse trains, average charge occupations are measured with a nearby quantum point contact as detector. A key component of our setup is a sample holder optimized for broadband radio frequency applications. Our setup can detect displacements of single electrons on time scales well below a nanosecond. Tunneling rates through individual barriers and relaxation times are obtained by using a rate equation model. We demonstrate the full characterization of a tunable double quantum dot using this technique, which could also be used for coherent charge qubit control

Analisis Implementasi Peraturan Daerah Nomor 2 Tahun 2011 Tentang Pajak Hotel Kategori Rumah Kost di Kota Manado

Sektor pajak adalah salah satu penerimaan Negara. Pajak daerah adalah pajak yang dipercayakan pemerintah pusat untuk dikelola pemerintah daerah. Pajak hotel kategori rumah kost termasuk dalam pajak daerah. Usaha rumah kost di Kota Manado mengalami pertumbuhan cepat. Ini membuat USAha rumah kost merupakan sektor potensial dalam peningkatan penerimaan pajak hotel. Tujuan penelitian ini untuk mengetahui apakah implementasi peraturan daerah nomor 2 tahun 2011 tentang Pajak Daerah khususnya pajak hotel kategori rumah kost telah berjalan dengan baik serta kendala yang dihadapi dalam pelaksanaan pemungutannya. Objek dalam penelitian ini adalah Dinas Pendapatan Daerah Kota Manado (DISPENDA) serta beberapa rumah kost di Lingkungan Kleak di Kota Manado. Metode penelitian yang digunakan adalah analisis deskriptif yaitu peneliti mengumpulkan data, menganalisa kemudian menarik kesimpulan. Hasil penelitian menunjukkan penerapan peraturan daerah nomor 2 Tahun 2011 terkait pajak hotel kategori rumah kost masih belum maksimal. terdapat kendala dalam pemungutan pajak rumah kost. Sebaiknya Dinas Pendapatan Daerah Kota Manado lebih meningkatkan sosialisasi kepada wajib pajak USAha rumah kost serta bertindak lebih tegas kepada wajib pajak dan apabila memungkinkan, sediakan fasilitas yang lebih memudahkan para pemilik rumah kost untuk menyetorkan pajaknya tanpa mendatangi kantor DISPENDA

The thin film iris

Thin film microwave irises with capacitive reactanc

Parallel Quantum-Point-Contacts as High-Frequency-Mixers

We present the results of high-frequency mixing experiments performed upon parallel quantum point-contacts defined in the two-dimensional electron gas of an Al_{x}Ga_{1-x}As/GaAs-heterostructure. The parallel geometry, fabricated using a novel double-resist technology, enables the point-contact device to be impedance matched over a wide frequency range and, in addition, increases the power levels of the mixing signal while simultaneously reducing the parasitic source-drain capacitance. Here, we consider two parallel quantum point-contact devices with 155 and 110 point-contacts respectively; both devices operated successfully at liquid helium and liquid nitrogen temperatures with a minimal conversion loss of 13 dB.Comment: 4 figures, RevTeX, to be published in the 16 June 1997 issue of Applied Physic Letter

A 20 Ghz Depolarization Experiment Using the ATS-6 Satellite

A depolarization experiment using the 20 GHz downlink from the ATS-6 satellite was described. The following subjects were covered: (1) an operational summary of the experiment, (2) a description of the equipment used with emphasis on improvements made to the signal processing receiver used with the ATS-5 satellite, (3) data on depolarization and attenuation in one snow storm and two rain storms at 45 deg elevation, (4) data on low angle propagation, (5) conclusions about depolarization on satellite paths, and (6) recommendations for the depolarization portion of the CTS experiment

A depolarization and attenuation experiment using the CTS satellite. Volume 1: Experiment description

An experiment for measuring precipitation attenuation and depolarization on the Communications Technology Satellite (CTS) 11.7 GHz downlink is described. Attenuation and depolarization of the signal received from the spacecraft is monitored on a 24 hour basis. Data is correlated with ground weather conditions. Theoretical models for millimeter wave propagation through rain are refined for maximum agreement with observed data. Techniques are developed for predicting and mimimizing the effects of rain scatter and depolarization on future satellite communication systems