Nippon Hoso' Kyokai

Other

Murata Manufacturing Co., Ltd.

Shin-etsu Chemical Co., Ltd.

Toshihiro Nomoto

Toshihiko Ryuo

Masayuki Tanno

Masanori Ikari

Takao Kuki

Takekazu Okada

Satoru Shinmura

Fumio Kanaya

Shigeyuki Itoh

Youhei Ishikawa

Tomohiro Saito

Shoji Tanaka

Akinori Hashimoto

Shinichiro Ichiguchi

Hisakazu Katoh

Junji Kumada

Hajime Matsumura

Kazuhiko Shibuya

Fumiaki Minematsu

Toshihito Umegaki

Yuichi Iwadate

Kouichi Takano

Hitoshi Nakagawa

Akira Toba

Hiroyuki Hamazumi

Masaru Takechi

Akihiko Nemoto

Insulating ceramic parts for insulating collector electrodes in a traveling wave tube and a vacuum envelope are formed in a cylindrical shape in which the central axis of the inner diameter diverges from the central axis of the outer diameter and are constructed such that holes are provided in portions of the insulating ceramic parts where the thickness in the radial direction is great, and high-voltage leads for supplying prescribed voltages to said collector electrodes from the exterior pass through these holes.

Traveling wave tube

Stabilized carrier recovery is achieved even at the time of a low C/N ratio by measuring the phase of a signal and controlling VCO or NCO (Numerical Controlled Oscillator) using only a period having few constellation points. At this time, false lock phenomenon is avoided as follows. That is, relatively short SYNC modulated by an already-known pattern is entered into a modulation wave, VCO or NCO oscillation frequency is swept in a wide range and sweep is stopped at a frequency in which the SYNC can be received, thereby carrying out coarse control AFC. Further, a period having long to some extent, having few constellation points is provided in the modulation wave and then, a difference between the frequency of a received modulated signal and a local oscillation signal of VCO or NCO is obtained in this period. This frequency difference is analyzed according to the phase differential function method, self-correlation function method or count method, and the VCO or NCO is controlled based on this result of analysis.

AFC circuit, carrier recovery circuit and receiver device capable of regenerating a carrier reliably even at the time of low C/N ratio

A magnetostatic wave device includes a Gd,Ga,O,substrate off-angled from a &lcub;110&rcub; plane. A magnetic thin film including a crystal of garnet is formed on the Gd,Ga,O,substrate by liquid-phase epitaxy. A transducer operates for exciting magnetostatic wave in the magnetic thin film in response to an RF electric signal. A bias magnetic field is applied to the magnetic thin film. There is a relation as 20&deg;&lE;&verbar;&thgr;,&plus;&thgr;,&verbar;&lE;35&deg;, where &ldquo;&thgr;,&rdquo; denotes an angle between a longitudinal direction of the transducer and a <001> orientation of the crystal in the magnetic thin film, and &ldquo;&thgr;,&rdquo; denotes an angle between a transverse direction of the transducer and a specified direction. The specified direction is parallel to a line of intersection between a horizontal plane of the magnetic thin film and a given plane which is perpendicular to the horizontal plane of the magnetic thin film and which contains a direction of the bias magnetic field. Also, there is a relation as &verbar;&thgr;,&verbar;&lE;75&deg;, where &ldquo;&thgr;,&rdquo; denotes an angle between the specified direction and the direction of the bias magnetic field.

Magnetostatic wave device with specified angles relating the transducer, magnetic thin film, and bias magnetic field

An S/N enhancer is provided which can be formed to be small in size and in which impedance matching can easily be achieved. The S/N enhancer includes two magnetostatic wave elements. First to fourth transducers each in the shape of a single line are disposed on YIG thin films of the magnetostatic wave elements in parallel and spaced from one another. An input terminal is connected to one end of the first transducer. An attenuator is connected between the other end of the first transducer and one end of the third transducer. A 180.degree. shifter and another attenuator are connected in series between one end of the second transducer and one end of the fourth transducer. An output terminal is connected to the other end of the fourth transducer. The other ends of the second and third transducers are respectively grounded.

Magnetostatic wave distributor, synthesizer and S/N enhancer

A magnetostatic wave device includes a Gd.sub.3 Ga.sub.5 O.sub.12 substrate off-angled from a {110} plane. A magnetic thin film including a crystal of garnet is formed on the Gd.sub.3 Ga.sub.5 O.sub.12 substrate by liquid-phase epitaxy. A transducer is operative for exciting magnetostatic wave in the magnetic thin film in response to an RF electric signal. A bias magnetic field is applied to the magnetic thin film. There is a relation as 20.degree..ltoreq..vertline..theta..sub.1 +.theta..sub.2 .vertline..ltoreq.35.degree., where '.theta..sub.1 ' denotes an angle between a longitudinal direction of the transducer and a &lt;001&gt; orientation of the crystal in the magnetic thin film, and '.theta..sub.2 ' denotes an angle between a direction of the bias magnetic field and a transverse direction of the transducer which is perpendicular to the longitudinal direction thereof.

Magnetostatic wave device

A reflection-type S/N enhancer includes a Gd.sub.3 Ga.sub.5 O.sub.12 substrate off-angled from a {110} plane. A magnetic thin film including a crystal of garnet is formed on the Gd.sub.3 Ga.sub.5 O.sub.12 substrate by liquid-phase epitaxy. The magnetic thin film has a saturation magnetization in a range of 500 G to 1,100 G. A transducer is operative for exciting magnetostatic wave in the magnetic thin film in response to an RF electric signal. A bias magnetic field is applied to the magnetic thin film. There is a relation as .vertline..theta..sub.1 +.theta..sub.2 .vertline.&lt;45.degree., where '.theta..sub.1 ' denotes an angle between a longitudinal direction of the transducer and a &lt;001&gt; orientation of the crystal in the magnetic thin film, and '.theta..sub.2 ' denotes an angle between a direction of the bias magnetic field and a transverse direction of the transducer in a horizontal plane. The transverse direction of the transducer is perpendicular to the longitudinal direction thereof.

Reflection-type S/N enhancer

A signal-to-noise enhancer 10 includes a first 90 degree hybrid set 20. A first output end of the first 90 degree hybrid set 20 is connected to an input end of a limiter used a magnetostatic wave element 62a utilized the magnetostatic surface wave mode. Also, a second output end of the first 90 degree hybrid set 20 is connected to an input end of a filter used a magnetostatic wave element 62b similar to the magnetostatic wave element 62a in structure, via a resistor 32 as a first attenuator. Furthermore, an output end of the limiter is connected to a first input end of a second 90 degree hybrid set 40 via a resistor 52 as a second attenuator. Also, an output end of the filter is connected to a second input end of the second 90 degree hybrid set 40.

Signal-to-noise enhancer

A magnetostatic wave (MSW) signal-to-noise (S/N) enhancer includes a divider for dividing an input signal into a first and a second path signals, first and second microwave-MSW transducers for transducing the first and second path signals into the first and second path transduced signals, and a combiner for combining the first and second path transduced signals in opposite phase to each other. The first path signal contains a desired signal which is higher than a first saturation level and a noise component which is lower than the first path threshold power level. The first microwave-MSW transducer outputs the noise in linear operation and the desired signal in saturation operation. All the component signals of the second path signal including noise are lower than the second path threshold power level and are output in a linear operation by the second microwave-MSW transducer.

Magnetostatic wave S/N enhancer and receiving apparatus of FM or PM

Growing community of inventors

Tokyo, Japan

Toshihiro Nomoto