摘要:
A nuclear spin control device comprises a first semiconducting layer with spin-up carriers, a second semiconducting layer with spin-down carriers; and a third semiconducting layer arranged between the first and the second semiconducting layers. The third semiconducting layer can be tunnelled selectively by the spin-up carriers and the spin-down carriers such that nuclear spin in the third semiconducting layer selectively interacts with the carriers so as to be oriented into a desired direction. The device may be adapted to control the shape of a wave function so as to cover nuclear spins in the third semiconducting layer and propagate information of one nuclear spin to another nuclear spin.
摘要:
A balun circuit comprising first through third CPW lines becoming signal I/O ports, a first differential transmission line for linking the central conductor of the second CPW line and the ground conductor of the first CPW line and for linking the ground conductor of the second CPW line and the central conductor of the first CPW line, a second differential transmission line for linking the central conductors of the first and third CPW lines and for linking the ground conductors of the first and third CPW lines, and a joint for connecting at least two ground conductors of the first through third CPW lines. The differential transmission line has a first line formed in a dielectric layer on a substrate, a second line arranged in the underlying layer, and an underlying line at a fixed potential arranged between the substrate and the second line.
摘要:
A bit error rate of the reception signal is detected on the reception side, such that an n optimal modulation method and LO output power are determined in accordance with this bit error rate, and an LO output changing instruction is sent to an image signal rejection mixer on the transmission side. The image signal rejection mixer changes the phase X=α+γ in response to the LO output changing instruction when power splitter (201) splits the LO into two components with equal amplitude and phase difference α, power splitter (202) splits the IF signal into two components with equal amplitude and phase difference β, and power combiner (205) combines RF signals with equal amplitude and phase difference γ. By changing the X, the LO output power is controlled and the back-off amount of a transmission amplifier is changed in accordance with an optimal modulation scheme. In this event, α−β+γ=2nπ (n is an integer) is set so as to maximize the image signal rejection amount.
摘要:
A 0-to-90-degree phase shifter (13) includes a voltage-variable power supply (16), a transistor (17), a 90-degree divider (18), gain-variable amplifiers (19) (19-1 and 19-2), and a combiner (20). The 90-degree divider (18) divides an input signal into a signal to which a 90-degree phase is given and a signal to which no phase is given, and outputs the divided signals to the gain-variable amplifiers (19). The gain-variable amplifiers (19) (19-1 and 19-2) output signals whose amplitudes are changed according to a phase control amount to the combiner (20). The combiner (20) combines the signals input from the two gain-variable amplifiers (19) and outputs the combined signal. The impedance between the source and the drain of the transistor connected to the isolation port of the 90-degree divider (18) can be changed as appropriate.
摘要:
To reduce time to point a directional wireless portable terminal (WPT) to an access point (AP) when data is downloaded from the AP to the WPT, a user points the WPT to the AP, performs a first operation and transmits a request of authentication and download to the AP. The AP requests a server to perform the authentication and the download. The server transmits information on a current situation to the AP. The AP calculates time required until the download can be started based on content capacity and the like and transmits information on the calculated time to the WPT. The WPT displays countdown until the download can be started. During that time, the server performs the authentication and, if successful, delivers content to the AP. When the download can begin, the user performs a second operation and transmits a request of re-authentication and download to the AP.
摘要:
The present invention intends to improve communication efficiency between two communication apparatuses each engaged in the communication by full duplex communication method by using a surplus band of the one to transmission band of the other. A first bandwidth required by a first communication apparatus (A) at data transmission and a second bandwidth required by a second communication apparatus (B) at data transmission are presumed. Next, the first bandwidth presumed as mentioned is compared to a first bandwidth used which the first communication apparatus (A) currently uses and at the same time, the second bandwidth presumed as mentioned is compared to a second bandwidth used which the second communication apparatus (B) currently uses. The first bandwidth and the second bandwidth are then adjusted, and a third bandwidth which the first communication apparatus (A) uses at data transmission and a fourth bandwidth which the second communication apparatus (B) uses are determined.
摘要:
To reduce time to point a directional wireless portable terminal (WPT) to an access point (AP) when data is downloaded from the AP to the WPT, a user points the WPT to the AP, performs a first operation and transmits a request of authentication and download to the AP. The AP requests a server to perform the authentication and the download. The server transmits information on a current situation to the AP. The AP calculates time required until the download can be started based on content capacity and the like and transmits information on the calculated time to the WPT. The WPT displays countdown until the download can be started. During that time, the server performs the authentication and, if successful, delivers content to the AP. When the download can begin, the user performs a second operation and transmits a request of re-authentication and download to the AP.
摘要:
A bit error rate of the reception signal is detected on the reception side, such that an n optimal modulation method and LO output power are determined in accordance with this bit error rate, and an LO output changing instruction is sent to an image signal rejection mixer on the transmission side. The image signal rejection mixer changes the phase X=α+γ in response to the LO output changing instruction when power splitter (201) splits the LO into two components with equal amplitude and phase difference α, power splitter (202) splits the IF signal into two components with equal amplitude and phase difference β, and power combiner (205) combines RF signals with equal amplitude and phase difference γ. By changing the X, the LO output power is controlled and the back-off amount of a transmission amplifier is changed in accordance with an optimal modulation scheme. In this event, α−β+γ=2nπ (n is an integer) is set so as to maximize the image signal rejection amount.
摘要:
A negative resistance circuit having a transistor and a plurality of distributed constant lines respectively connected to the three terminals of the transistor further comprises an inductive element or a capacitive element connected between the output terminal of the negative resistance circuit and the ground potential. The negative resistance is adjusted through the inductance of the inductive element or the capacitance of the capacitive element.
摘要:
In a phased array antenna radio communication apparatus including a plurality of antennas, a radio communication apparatus is provided which can reduce an influence of the local leak signals on the radiation direction of transmission signals. Local signal phase shifters 11-1 to 11-h are used to control phases of local signals to be input to quadrature modulators 13-1 to 13-h, and baseband signal phase shifters 12-1 to 12-h are used to control phases of baseband signals to be input to the quadrature modulators 13-1 to 13-h. The radiation direction of the local leak signals to be sent from transmission antennas 15-1 to 15-h can be controlled by the local signal phase shifters 11-1 to 11-h, and the radiation direction of the transmission signals can be controlled by both of the local signal phase shifters 11-1 to 11-h and the baseband signal phase shifters 12-1 to 12-h.