公开(公告)号：EP1018214A1

公开(公告)日：2000-07-12

申请号：EP98948975.2

申请日：1998-09-14

申请人： Italtel s.p.a.

发明人： POLITI, Marco

IPC分类号： H03D9/06

CPC分类号： H03D9/0633

摘要： It is described an image rejection, sub-harmonic frequency converter, realized in microstrip, particularly adapted to be used in mobile communication equipment. The converter avails of two identical sub-harmonic mixers employing each one or two pairs of diodes in antiparallel, obtained on a same silica substrate, and of a structure of hybrids performing appropriate phase combination adapted to suppress the image band in the converted signal. The mixers include filtering structures preferably consisting, but no limited to the same, of stubs μ/4 long, at the local oscillator frequency, having a free end, in short or open circuit, respectively. According to an alternative embodiment, said stubs are replaced by appropriate filters implemented with concentrated structures (L and C) performing the same transfer function of the stubs in microstrip. The sub-harmonic converter and a traditional converter can be jointly employed in a terminal mobile equipment operating in 'Dual Mode service hand-held' (GSM 900 and DCS 1800) sharing a unique 900 MHz local oscillator.

公开(公告)号：EP1018223A1

公开(公告)日：2000-07-12

申请号：EP98951372.6

申请日：1998-09-10

申请人： Italtel s.p.a.

发明人： MADDIOTTO, Massimo ,  POLITI, Marco

IPC分类号： H04B1/30 ,  H03D7/16

CPC分类号： H04B1/0092 ,  H03D7/166 ,  H04B1/005 ,  H04B1/30

摘要： It is described a broad band digital radio receiver for multicarrier signals, such as for instance TACS or GSM, employing a quadrature demodulator (DEMI/Q) to directly shift in base band the radiofrequency signal. To this purpose, a local oscillator is used, having frequency f0 placed at the centre of the radiofrequency BW band, in order that pairs of channels, symmetric versus f0 are superimposed in the lower base half-band. The equivocation originated in the base band is then solved by second orthogonal demodulators (DEMx/y), of numeric type, which supply pairs of twice demodulated signals that can be grouped in four-equation systems in the four unknown values consisting of the components, in phase and in quadrature, of the two channels of each pair. Subsequent reconstruction networks (RSCOR) solve the relevant systems and give the two components of each single channel for each pair. One (RSBIL) network is foreseen in the receiver, measuring the amplitude and phase dissymmetries in the two branches of the analogue demodulator and supplying four corresponding digital coefficients (a, b, c, d) to the reconstruction network, which is thus able to conunterbalance at output the effect due to dissymmetries.

公开(公告)号：EP1018223B1

公开(公告)日：2002-11-13

申请号：EP98951372.6

申请日：1998-09-10

申请人： Italtel S.p.a.

发明人： MADDIOTTO, Massimo ,  POLITI, Marco

IPC分类号： H04B1/30 ,  H03D7/16

CPC分类号： H04B1/0092 ,  H03D7/166 ,  H04B1/005 ,  H04B1/30

公开(公告)号：EP1021900A2

公开(公告)日：2000-07-26

申请号：EP98942671.3

申请日：1998-07-24

申请人： Italtel s.p.a.

发明人： BADA', Anna, Marina ,  POLITI, Marco

IPC分类号： H04L27/26 ,  H04L5/06

CPC分类号： H04L5/06 ,  H04B1/406 ,  H04L27/02

摘要： The transmitter modulates a number of communication channels which are summed to generate a sampled sequence of the digital multicarrier signal. The sample sequence is converted into an analogue sequence via a D/A converter. The sequence is then bandpass filtered at intermediate frequency in order to select an n-th replica of the baseband spectrum of the multicarrier signal. The selection is based on the maximum distance between the replica and DC. The selected replica is then upconverted to radio-frequency, bandpass filtered, amplified and coupled to an antenna.

公开(公告)号：EP1038366A1

公开(公告)日：2000-09-27

申请号：EP98961242.9

申请日：1998-11-26

申请人： Italtel s.p.a.

发明人： DONATI, Marcello ,  POLITI, Marco

IPC分类号： H04B17/00

CPC分类号： H04B17/20

摘要： It is described a testing system of the receivers of a base transceiver station for cellular telephone systems, for instance GSM 900 MHz, or DCS 1800 MHz, or TACS, etc., equipped with intelligent array antenna having N sensors. The system consists of a radiofrequency scenario simulation equipment (SIM_RF), governed by a control processor (CONTR_PC), both connected to the bus of an Ethernet network, to which the device under testing (DUT) is also connected. The simulation equipment generates on N outputs (out1, out2..., outN) a complex signal consisting of N identical radiofrequency signals (RF1, RF2,.., RFN) differing among them for a phase progessive value. These signals are withdrawn by a same number of coaxial cables and conveyed towards the N antenna input connectors (in1, in2,..., inN) of the radiofrequency signals of the receiver to be tested. The N test signals are obtained through local generation of as many groups of N digital isofrequential carriers as are required to simulate the directions of a useful signal with an arbitrary number of echoes of the same, and the directions of an arbitary number of isofrequential interferent carriers, and not, with their relevant echoes. The N carriers of each group are then modulated with appropriate modulation and digitally multiplied by a same number of relevant beamforming coefficients producing, within each group, an ordering according to gradually increasing phase values.