摘要:
Configuration of a connection between an even-harmonic mixer and a filter is simplified, thereby enabling size reduction. An even-harmonic mixer (21) and a high-frequency bandpass filter (23) are connected to each other via a transmission line (22), thereby forming a filter-integrated even-harmonic mixer. The length of the transmission line (22) is set so that impedance on the transmission line side as viewed from a connection point (24) between the even-harmonic mixer (21) and the transmission line (22) is approximately 0 for a frequency fLO of a local oscillation signal. This allows elimination of an open stub which is used in a conventional even-harmonic mixer and of which the line length to provide equivalent grounding for the frequency fLO is about 1 mm. Thus, the connection portion between the even-harmonic mixer and the high-frequency bandpass filter is simplified and a compact circuit layout for the filter-integrated even-harmonic mixer is obtainable.
摘要:
A top panel, which is disposed to face a module board with an electronic component therebetween, includes a resin layer and a metal layer, and has an insulating characteristic. The metal layer includes a metal layer formed at a front side of the resin layer and a metal layer formed at a rear side of the resin layer. With this structure, in reflow soldering performed in mounting a semiconductor module on a main board, warp which is caused, under temperature change, in the top panel due to difference in coefficient of thermal expansion between the resin layer and the metal layer formed at the front side of the resin layer is cancelled by warp which is caused, under temperature change, in the top panel due to difference in coefficient of thermal expansion between the resin layer and the metal layer formed at the rear side of the resin layer, whereby warp of the top panel is eliminated. This helps prevent the electronic component adhered to the top panel with adhesive from being pressed down to or pulled up from the module board due to warp of the top panel.
摘要:
A bias circuit includes: a first transistor having a base terminal grounded via a resistor, and a collector terminal connected to a first power supply port via an adjustment resistor; a second transistor having an emitter terminal connected to the base terminal of the first transistor, and a base terminal connected to the collector terminal of the first transistor; a third transistor having a base terminal connected to the base terminal of the first transistor, and a collector terminal connected to the first power supply port via an adjustment resistor; and a fourth transistor having a base terminal connected to the collector terminal of the third transistor, a current being taken out from the emitter terminal of the fourth transistor. This arrangement makes it possible to suppress a consuming current and output a bias current that is more stable against a temperature change and/or a power supply voltage change.
摘要:
A bias circuit includes: a first transistor having a base terminal grounded via a resistor, and a collector terminal connected to a first power supply port via an adjustment resistor; a second transistor having an emitter terminal connected to the base terminal of the first transistor, and a base terminal connected to the collector terminal of the first transistor; a third transistor having a base terminal connected to the base terminal of the first transistor, and a collector terminal connected to the first power supply port via an adjustment resistor; and a fourth transistor having a base terminal connected to the collector terminal of the third transistor, a current being taken out from the emitter terminal of the fourth transistor. This arrangement makes it possible to suppress a consuming current and output a bias current that is more stable against a temperature change and/or a power supply voltage change.
摘要:
Disclosed herein is a method for determining the drug sensitivity of a microbe which comprises pouring a microbial suspension into each of the compartments or wells at a position which is in the vicinity of an electrode for measuring dissolved oxygen concentration, measuring current from each electrode at a second time interval for a third time period, each time is obtained based upon each of the measured currents at which the maximum current is obtained, obtaining each current value within a fourth time period which starts from the time at which the maximum current is obtained, detecting drug sensitivity based upon the variation condition of each current value during the fourth time period. The method allows rapid drug susceptibility measurements.
摘要:
A balanced power amplifier includes grounded-emitter first and second bipolar transistors that are disposed in parallel, first and second variable impedance elements with each one end being electrically connected to each base of the first and second bipolar transistors, a regulator circuit disposed between the other end of the first variable impedance element and the other end of the second variable impedance element, a first resistance for electrically connecting the line between the first variable impedance element and the regulator circuit and a voltage source, and a second resistance for electrically connecting the line between the second variable impedance element and the regulator circuit and the voltage source. The balanced power amplifier is small in the number of component parts and in size.
摘要:
A power amplifier includes a front-stage amplifier including first and second transistors connected in parallel, and a rear-stage amplifier including a third transistor. The first transistor is biased into near-Class A without a distortion compensation circuit. The second and third transistors are biased into near-Class B with a distortion compensation circuit. The gain characteristics of the first to third transistors are adjusted so that the concave portion of the gain characteristics of the front-stage amplifier and the convex portion of the gain characteristics of the rear-stage amplifier match each other, to thereby flatten the gain characteristic of the entire power amplifier.
摘要:
In the radio communication device of the present invention, a first carrier transmission modulation wave outputted from a first signal generator 101 is amplified by a first power amplifier 103 and transmitted from a first antenna element 107 through a first duplexer 105. A second carrier transmission modulation wave outputted from a second signal generator 102 is amplified by a second power amplifier 104 and transmitted from a second antenna element 108 through a second duplexer 106. Then, transmission modulation waves with the first and second carriers are subjected to spatial power combining after being transmitted from the two antenna elements 107 and 108 that permit diversity reception. As a result, the radio communication device, which uses two or more carriers (carrier waves), can achieve highly efficient power amplification with a small-sized low-cost circuit means.
摘要:
The input side and the output side of a first bandpass filter circuit BPF1a are magnetically coupled to each other in a jump-coupling manner by the first mutual inductance (L31a, L41a) for connection between an input port IN and the input side of the first bandpass filter circuit BPF1a and connection between an output port OUT and the output side of the bandpass filter circuit BPF1a. The input side and the output side of a second bandpass filter circuit BPF2a whose center frequency is higher than that of the first bandpass filter circuit BPF1a are magnetically coupled to each other in a jump-coupling manner by the second mutual inductance (L32a, L42a) for connection between the input side of the first bandpass filter circuit BPF1a and the input side of the second bandpass filter circuit BPF2a and connection between the output side of the first bandpass filter circuit BPF1a and the output side of the second bandpass filter circuit BPF2a. This multiband filter circuit is capable of improving the degree of steepness by generating a number of transmission zeros in the vicinity of a plurality of passbands with a simple construction.
摘要:
A means for detecting a presence of a particular material in the air, a filter for an air conditioner which can confirm the presence of the particular material in the air, and a method for confirming a performance of the filter for an air conditioner about a removal of the particular material and/or a lifetime of the filter for an air conditioner are provided. The particular material present in the air is detected by a color change of a colorimetric sensor comprising a receptor molecule specifically binding with the particular material in the air, and a polymer molecule whose light absorbency is altered due to binding of the particular material and the receptor molecule.