Abstract: A method of obtaining velocity of detonation (VOD) information from a borehole wherein an explosive in the borehole is ignited by initiation of a detonator, the method including the steps of using a control circuit which obtains a measurement of the VOD and which is subsequently destroyed by ignition of the explosive, and of transmitting from the borehole a wireless signal which contains the VOD measurement and data which identifies the borehole before the control circuit is destroyed.

Abstract: A communication module which is linked to a detonator which is initiated in response to a fire command signal, and wherein the communication module includes a transmitter which transmits a wireless signal which is dependent upon initiation of the detonator and which contains or conveys an identifier which uniquely identifies the detonator.

Abstract: Exemplary embodiments are disclosed of flexible antennas, such as flexible planar inverted “F” antenna (PIFAs), inverted flexible PIFAs, flexible elevated notch antennas, flexible freestanding PIFAs, antenna systems including the same, etc. In exemplary embodiments, an inverted flexible PIFA includes a bottom-side radiating element and is configured for an inverted mount to a mounting surface whereby a radiation pattern of the bottom-side radiating element is directed outwardly away from the mounting surface.

Abstract: A communication module which is linked to a detonator which is initiated in response to a fire command signal, and wherein the communication module includes a transmitter which transmits a wireless signal which is dependent upon initiation of the detonator and which contains or conveys an identifier which uniquely identifies the detonator.

Abstract: A method of obtaining velocity of detonation (VOD) information from a borehole wherein an explosive in the borehole is ignited by initiation of a detonator, the method including the steps of using a control circuit which obtains a measurement of the VOD and which is subsequently destroyed by ignition of the explosive, and of transmitting from the borehole a wireless signal which contains the VOD measurement and data which identifies the borehole before the control circuit is destroyed.

Abstract: Exemplary embodiments are disclosed of dual-band multiple-input multiple-output (MIMO) antennas. In an exemplary embodiment, an antenna generally includes a circuit board, a first antenna radiating element positioned on the circuit board, a second antenna radiating element positioned on the circuit board, and at least two antenna feeding elements extending from the circuit board. Each of the at least two antenna feeding elements is electrically connected with a different one of the first and second antenna elements.

Abstract: Exemplary embodiments are disclosed of dual-band multiple-input multiple-output (MIMO) antennas. In an exemplary embodiment, an antenna generally includes a circuit board, a first antenna radiating element positioned on the circuit board, a second antenna radiating element positioned on the circuit board, and at least two antenna feeding elements extending from the circuit board. Each of the at least two antenna feeding elements is electrically connected with a different one of the first and second antenna elements.

Abstract: A flexible inverted “F” antenna (PIFA) is shown. The flexible PIFA is not only applicable to flat surfaces, but it can be applied to curved surfaces, both convex and concave, without degrading performance. The flexible PIFA can also be used close to living bodies or to a metal surface without detuning. The flexible PIFA is formed from a flexible printed circuit board (PCB) having a metal layer on one side and over which a cover layer is positioned. The flexible PCB is folded, on its reverse side, around a flexible dielectric element with the covered metal layer facing outward to form a metal conducting service, an impedance matching stub and a ground plate. An adhesive layer forms a portion of the ground plate that is not in contact with the dielectric element. This adhesive layer is applied against the desired surface. A coaxial cable is electrically coupled to corresponding feed and ground tabs at the short circuit plate portion of the flexible PIFA.

Abstract: A flexible inverted “F” antenna (PIFA) is shown. The flexible PIFA is not only applicable to flat surfaces, but it can be applied to curved surfaces, both convex and concave, without degrading performance. The flexible PIFA can also be used close to living bodies or to a metal surface without detuning. The flexible PIFA is formed from a flexible printed circuit board (PCB) having a metal layer on one side and over which a cover layer is positioned. The flexible PCB is folded, on its reverse side, around a flexible dielectric element with the covered metal layer facing outward to form a metal conducting service, an impedance matching stub and a ground plate. An adhesive layer forms a portion of the ground plate that is not in contact with the dielectric element. This adhesive layer is applied against the desired surface. A coaxial cable is electrically coupled to corresponding feed and ground tabs at the short circuit plate portion of the flexible PIFA.

Abstract: A wideband receiver antenna that utilizes a right-circular cylinder-based reflector which is positioned one arc segment away from a di-pole receiving element for use with high definition television signal reception as well as FM receiver reception.

Abstract: A biasing network for use in conjunction with a mixer employing field effect transistors which provides for minimum conversion loss over a range of process and temperature conditions. The biasing circuit includes a first field effect transistor having a small gate periphery which is configured as a current source, a second or reference field effect transistor having a gate periphery substantially equal to the gate peripheries of the transistors in the mixer to which the biasing circuit is providing DC biasing voltages and a voltage divider which is functional in defining operating conditions for the reference transistor.